In short: Trigonometry assignment help from FLN Tutors means a maths tutor solves your identities, trig equations, triangle problems and graph questions with you, explaining the method behind each step. Tutors solve and explain trigonometric ratios, identities, equations, graphs, the sine and cosine rules, radians and inverse functions step by step, so you can follow every line and answer similar questions on your own. Matched to a verified specialist who knows your course, your university's marking criteria, and your deadline.
Topics we cover
FLN trigonometry tutors cover everything from right-angled triangles and SOH CAH TOA at GCSE to the sine and cosine rules, radians, graphs of trig functions, identities and solving trig equations at A-Level and university. Sessions use your own homework and past papers, and the tutor shows each step and why it works, so you can recognise which rule a question needs.
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Trigonometry is the branch of mathematics that studies the relationships between the angles and side lengths of triangles, and the periodic functions (sine, cosine and tangent) that arise from them. It is used to find unknown sides and angles, model waves and cycles, and solve problems in physics, engineering, surveying and navigation.
A tutor uses the same method on your own questions, so you can repeat it in exams.
Trigonometry help is one-to-one support from a tutor who explains each method step by step, works through problems from your own course and shows you how marks are awarded. At FLN Tutors it covers live online tutoring, worked homework solutions and guidance on trigonometry assignments, so you understand the method and can use it yourself in the exam.
| What you need | Best option | What you get |
|---|---|---|
| Regular lessons through a GCSE, A-Level, IB or university maths course | Live one-to-one tutoring | A tutor explains the method on a shared whiteboard at your pace |
| A few questions you are stuck on | Homework help | Step-by-step worked solutions you can learn from |
| A graded trigonometry assignment or problem set | Assignment help | Tutor guidance, feedback and model workings within your university's rules |
This map lists the core trigonometry topics, the point where students most often get stuck, and how a tutor helps you past it.
| Topic | Where students get stuck | How a tutor helps |
|---|---|---|
| Right-angled triangles | Labelling opposite, adjacent and hypotenuse | Label from the angle every time, then choose the ratio |
| Sine and cosine rules | Choosing the right rule; the ambiguous case | A decision checklist based on what is given |
| Radians | Switching between degrees and radians | Practice converting and spotting π |
| Graphs and transformations | Period and phase shift of y = a sin(bx + c) | Sketch step by step, one transformation at a time |
| Equations | Missing solutions in the range | CAST or graph method for every solution |
| Identities | Knowing where to start a proof | Start from the harder side and target the other |
| Calculus with trig | Chain rule and integrating sin² x | Use the double angle identity to rewrite first |
Trigonometry formulas fall into four groups: the right-angled ratios (SOH CAH TOA), the sine and cosine rules for any triangle, the Pythagorean and reciprocal identities, and the compound and double angle formulae. Tutors explain where each formula comes from and when to use it, so you choose the right one quickly in an exam.
| Formula | When to use it |
|---|---|
| sin θ = opp/hyp, cos θ = adj/hyp, tan θ = opp/adj | Right-angled triangles (SOH CAH TOA) |
| a/sin A = b/sin B = c/sin C | Sine rule: a side and its opposite angle are known |
| a² = b² + c² − 2bc cos A | Cosine rule: two sides and the included angle, or all three sides |
| Area = ½ab sin C | Area of any triangle |
| sin²θ + cos²θ = 1, tan θ = sin θ / cos θ | Simplifying and proving identities |
| sin 2A = 2 sin A cos A, cos 2A = cos²A − sin²A | Double angle formulae (A-Level and IB) |
| π radians = 180°, arc length s = rθ, sector area = ½r²θ | Radian measure (θ in radians) |
Exact values for 0°, 30°, 45°, 60° and 90° come up in non-calculator papers, so it pays to know them or to rebuild them from two special triangles: half of an equilateral triangle (30° and 60°) and a right-angled isosceles triangle (45°).
| Angle | sin | cos | tan |
|---|---|---|---|
| 0° | 0 | 1 | 0 |
| 30° (π/6) | 1/2 | √3/2 | 1/√3 |
| 45° (π/4) | √2/2 | √2/2 | 1 |
| 60° (π/3) | √3/2 | 1/2 | √3 |
| 90° (π/2) | 1 | 0 | undefined |
Tutors match your level, syllabus and exam board, from school to PhD.
| Level | What you study | Matching help |
|---|---|---|
| GCSE and IGCSE | SOH CAH TOA, exact values, sine and cosine rules, ½ab sin C, 3D problems, trig graphs (Higher) | GCSE Edexcel Maths Higher, IGCSE Maths Extended; specs: AQA 8300, Edexcel GCSE |
| A-Level | Radians, arcs and sectors, graphs and transformations, identities, equations, compound and double angles, R sin(x + α), small angles, calculus of trig functions | A-Level Mathematics; specs: AQA 7357, Edexcel, OCR A H240, Cambridge 9709 |
| IB and AP | Unit circle, identities, equations and trig models in IB Maths; trig functions in AP Precalculus and AP Calculus | IB Maths AA SL, AP Calculus AB |
| India (Classes 10 to 12, JEE) | Introduction to trigonometry, trigonometric functions, inverse trigonometric functions | JEE Mathematics Preparation |
| Undergraduate | Inverse and hyperbolic functions, Euler's formula, Fourier series, trig substitution in integrals | Engineering Mathematics and homework help |
| Master's and PhD | Trigonometric series and harmonic analysis in signal processing, physics and applied maths research | Live tutoring with a specialist |
Solving a trigonometric equation means finding every angle in a given range that satisfies it. Isolate the trigonometric function, find the principal value with the inverse function, then use the graph or CAST diagram to find every other solution in the range. Tutors teach this as a routine so you never miss a solution.
Here is a typical A-Level question: solve 2 sin²x − sin x − 1 = 0 for 0° ≤ x < 360°.
| Step | Working |
|---|---|
| Treat it as a quadratic in sin x | Let s = sin x, so 2s² − s − 1 = 0 |
| Factorise | (2s + 1)(s − 1) = 0, so s = −1/2 or s = 1 |
| Solve sin x = 1 | x = 90° |
| Solve sin x = −1/2 | Principal value −30°; sine is negative in the third and fourth quadrants, so x = 180° + 30° = 210° and x = 360° − 30° = 330° |
| Check the range | All three answers lie in 0° ≤ x < 360° |
| Answer | x = 90°, 210°, 330° |
The most common mistake is stopping at the calculator value of −30°, which is outside the range, and missing 210° and 330°.
A calculator gives only one principal value, so you must find the rest yourself.
Example: solve sin x = 0.5 for 0° ≤ x ≤ 360°. The principal value is 30°, and the second is 180° − 30° = 150°, so x = 30° or 150°.
Here is a typical GCSE Higher and A-Level question: in triangle ABC, a = 7 cm, b = 9 cm and the angle C between them is 60°. Find side c and the area.
| Step | Working |
|---|---|
| Choose the rule | Two sides and the included angle are known, so use the cosine rule |
| Cosine rule | c² = a² + b² − 2ab cos C = 49 + 81 − 2 × 7 × 9 × 0.5 = 130 − 63 = 67 |
| Side c | c = √67 ≈ 8.19 cm (3 s.f.) |
| Area | Area = ½ab sin C = ½ × 7 × 9 × sin 60° = 31.5 × 0.866 ≈ 27.3 cm² |
| Check | c lies between b − a = 2 and a + b = 16, so it is a possible length |
Keep √67 in your calculator for any later steps rather than using the rounded value.
To prove an identity, start from the more complicated side and use known identities to turn it into the other side, one clear step at a time. Don't treat the identity as an equation by doing the same thing to both sides; markers want a chain of equal expressions.
Most lost marks in trigonometry come from a handful of habits: the calculator in the wrong mode, missing solutions, losing accuracy by rounding early and using the sine rule when the cosine rule is needed. Each is easy to fix once you know to check for it.
| Mark-loser | What to do instead |
|---|---|
| Calculator in degrees when the question uses radians (or the reverse) | Check the mode before every question; π in the question usually means radians |
| Only one solution to an equation | Sketch the graph or use CAST to find every solution in the range |
| Dividing both sides by sin x or cos x | Factorise instead, or you lose the solutions where sin x = 0 |
| The ambiguous case of the sine rule | Check whether 180° minus the angle also gives a valid triangle |
| Rounding in the middle of a calculation | Keep full calculator values and round only the final answer |
| Identity proofs that work on both sides | Start from one side and finish on the other |
Trigonometry is assessed in several formats, and each one is marked on different things. Tutors help you understand the brief and the marking criteria before you start.
| Assessment | What markers look for |
|---|---|
| Exam papers (GCSE, A-Level, IB) | Clear method, exact values where asked, every solution in the range, correct accuracy |
| Homework and problem sheets | Complete working, a diagram where useful, answers checked |
| Proof questions | A logical chain from one side to the other, with each identity named |
| University assignments | Correct notation, justified steps and links to calculus or physics applications |
| Coursework or investigations | A clear question, accurate modelling with trig functions and evaluation of the model |
Trigonometry is mostly done by hand, but a few tools help you check work and see graphs.
| Tool | What it is used for | |
|---|---|---|
| Scientific or graphical calculator | Evaluating trig values; check degrees or radians mode first | |
| Desmos or GeoGebra | Plotting trig graphs and seeing transformations | |
| Wolfram | Alpha | Checking identities and equation solutions after you have tried them |
| Python or MATLAB | Modelling waves and periodic data at university |
Beyond the exam, trigonometry is the language of anything that rotates or repeats. Tutors show you how the same ideas reappear in later courses, which makes them easier to learn.
Related: Mathematics, Physics and Precalculus.
Trigonometry measures lengths and angles you cannot reach directly and describes anything that repeats in cycles.
| Field | How trigonometry is used |
|---|---|
| Architecture and construction | Roof pitches, ramp gradients and the heights of structures |
| Navigation and GPS | Bearings, distances and position fixing |
| Physics and engineering | Resolving forces, waves, alternating current and vibrations |
| Surveying | Heights of buildings and widths of rivers from measured angles |
| Computer graphics and games | Rotating and projecting objects on screen |
| Sound and music | Modelling sound waves as sine functions |
For free extra practice, the OpenStax Algebra and Trigonometry textbook from Rice University is reliable. Related FLN pages: precalculus foundations, calculus with trig derivatives and integrals, engineering mathematics and physics problems with vectors and waves.
Trigonometry is taught to similar core ideas worldwide, but grading, referencing and course structure differ. FLN tutors work from your own syllabus and handbook and schedule lessons in your time zone. Always follow your module handbook for referencing.
| Country | Where trigonometry is studied | Grading | Referencing usually used |
|---|---|---|---|
| United Kingdom | GCSE, A-Level and university maths | GCSE 9–1, A-level A*–E; degrees First, 2:1, 2:2, Third | Few citations; Harvard or numbered if required |
| United States | Geometry, Algebra 2, Precalculus, AP Precalculus; SAT Math | Letter grades A–F and a 4.0 GPA scale | Few citations; APA or numbered if required |
| Australia | Senior secondary maths such as VCE and HSC courses | HD, D, C, P at university; ATAR for school leavers | Harvard if required |
| Canada | Pre-calculus and Grade 11 to 12 functions courses | Letter grades or percentages; GPA scales vary by province and university | APA or numbered if required |
| India | CBSE and state boards, Classes 10 to 12; JEE | Board exam percentages; university CGPA, often on a 10-point scale | Few citations; as your university specifies |
Students in Ireland, the Gulf, Europe, Africa and Asia can book the same help, with lessons in their own time zone.
The price of trigonometry help depends on your level, how many questions you send and how soon you need the worked solutions. A short GCSE problem set costs less than a university Fourier series sheet. You always see the price first: a fixed quote for homework and assignment guidance, or the tutor's hourly rate for live lessons, with no contract and no minimum number of sessions. Refunds follow our refund policy.
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A trigonometry tutor works through your assignment with you rather than submitting it for you. They solve similar questions step by step, explain which rule or identity to use and why, and check your answers, so you understand the method and your final work stays your own.
It is a memory aid for right-angled triangles. Sine equals opposite over hypotenuse, cosine equals adjacent over hypotenuse, and tangent equals opposite over adjacent. Label the sides relative to the angle you are using first, then pick the ratio that links the side you know to the one you need.
Use the sine rule when you know a side and its opposite angle plus one more side or angle. Use the cosine rule when you know two sides and the angle between them, or all three sides. Neither needs a right angle, unlike SOH CAH TOA.
sin 30° = 1/2, sin 45° = √2/2 and sin 60° = √3/2. cos 30° = √3/2, cos 45° = √2/2 and cos 60° = 1/2. tan 30° = √3/3, tan 45° = 1 and tan 60° = √3. You can rebuild them from an equilateral triangle and a right-angled isosceles triangle.
Find the principal value with your calculator, then use the symmetry of the graph to find the second solution in each cycle. Add or subtract 360° for sine and cosine, or 180° for tangent, until you have every solution inside the interval given in the question.
Multiply degrees by π divided by 180 to get radians, and multiply radians by 180 divided by π to get degrees. So 90° is π/2 radians and π/3 radians is 60°. Always check your calculator is in the right mode before you start.
When you know two sides and a non-included angle, there can be two different triangles that fit. If the sine rule gives an angle θ, check whether 180° − θ also works with the other angle. If both add to less than 180°, there are two valid triangles.
The most common cause is the wrong angle mode: degrees instead of radians or the other way round. Other causes are missing brackets, such as typing sin 2x without brackets, and expecting the calculator to show every solution when it only gives the principal value.
Start from the more complicated side and work towards the other, using identities such as sin² x + cos² x = 1 and tan x = sin x / cos x. Rewrite everything in sin and cos if you are stuck, and do not treat the identity as an equation to solve.
sin 2x = 2 sin x cos x, and cos 2x can be written as cos² x − sin² x, 2cos² x − 1 or 1 − 2sin² x. tan 2x = 2 tan x ÷ (1 − tan² x). Choose the version of cos 2x that leaves only one trig function in your equation.
It rewrites a sin x + b cos x as a single sine wave, R sin(x + α), where R = √(a² + b²) and tan α = b ÷ a. This makes it easy to solve equations, find maximum and minimum values and sketch the graph. A-Level and IB questions use it often.
Start from the basic shape of y = sin x, y = cos x or y = tan x, then apply transformations: a vertical stretch changes the amplitude, a horizontal stretch changes the period, and translations shift the graph. Mark key points such as maxima, minima, intercepts and asymptotes.
sin⁻¹, cos⁻¹ and tan⁻¹ give an angle from a ratio. To make them functions, their outputs are restricted to principal ranges, such as −90° to 90° for sin⁻¹ and 0° to 180° for cos⁻¹. That is why other solutions must be found from the graph.
Many students find it hard at first because of the number of formulas and the need to find several solutions. It becomes much easier when you learn the exact values, understand the graphs and practise a fixed method for equations and identities with feedback on your working.
It is used in architecture and construction for slopes and heights, in navigation and GPS for bearings and positions, in physics and engineering for forces, waves and alternating current, in surveying, and in computer graphics and games to rotate and project objects on screen.
The price depends on your level, the number of sessions or questions and your deadline. You see the tutor's hourly rate or a fixed quote before you pay, with no contract and no minimum number of sessions. Short homework questions usually cost less than full assignments.
Yes. Tutors cover GCSE and IGCSE right-angled trigonometry and the sine and cosine rules, A-Level and IB identities, radians and R sin(x + α) form, and CBSE and ICSE class 10 to 12 trigonometry, including heights and distances and inverse trigonometric functions.
Yes. Tutors explain differentiating and integrating trig functions, trigonometric substitution, Fourier series basics and complex-number forms such as Euler's formula. They also help engineering and physics students who need trigonometry for vectors, waves, signals and mechanics problems, using worked examples from their own course.
Short questions can often be answered the same day, depending on tutor availability. Longer assignments or problem sets depend on the number of questions and your deadline, which you give when you ask for a quote. Asking early leaves time for follow-up questions.
Yes. Your files, questions and personal details are kept private and shared only with the tutor working on your request. We do not publish your work or contact your school or university, and you can ask for your files to be deleted once your request is complete.
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