How do I remember the trigonometry identities from C3 in the exam?

I often find it difficult to remember all the different identities, so what is useful is instead to just remember the familiar identity sin^2(x) + cos^2(x) = 1 that we have come across many times, and divide both sides by sin^2(x) and cos^2(x) respectively to obtain the two other identities you need.

JS

Related Maths A Level answers

All answers ▸

A particle of mass m moves from rest a time t=0, under the action of a variable force f(t) = A*t*exp(-B*t), where A,B are positive constants. Find the speed of the particle for large t, expressing the answer in terms of m, A, and B.


Using Pythagoras' theorem, show that sin^2(x)+cos^2(x)=1 for all x.


The rate of decay of the mass is modelled by the differential equation dx/dt = -(5/2)x. Given that x = 60 when t = 0, solve the quation for x in terms of t.


Integrate cos(2x)