Skip to main content

Back to the full dot-point answer

SingaporeAdditional MathematicsQuick questions

Trigonometry and Identities

Quick questions on Trigonometric identities and proofs explained: O-Level A-Maths

6short Q&A pairs drawn directly from our worked dot-point answer. For full context and worked exam questions, read the parent dot-point page.

What are the reciprocal identities?
Show answer
The three reciprocal ratios are defined as:
What are the Pythagorean identities?
Show answer
From x2+y2=1x^2 + y^2 = 1 on the unit circle comes the master identity, and dividing it through gives two more:
What is wrong rearrangement of the Pythagorean identity?
Show answer
From sin⁡2+cos⁡2=1\sin^2 + \cos^2 = 1, 1−cos⁡2θ=sin⁡2θ1 - \cos^2\theta = \sin^2\theta (not cos⁡2θ\cos^2\theta); check which one you need.
What is q1?
Show answer
Simplify sin⁡θcot⁡θ\sin\theta\cot\theta. [2 marks]
What is q2?
Show answer
Show that cos⁡2θ−sin⁡2θ≡1−2sin⁡2θ\cos^2\theta - \sin^2\theta \equiv 1 - 2\sin^2\theta. [2 marks]
What is q3?
Show answer
Simplify 1−cos⁡2θcos⁡2θ\dfrac{1 - \cos^2\theta}{\cos^2\theta}. [2 marks]

Have a question we have not covered?

This dot-point answer is short enough that we have not extracted many short questions yet. Read the full dot-point answer or ask Mo, our study assistant, in the chat for follow ups.

All Additional MathematicsQ&A pages