Question

state and prove double angle theorem​

Answer 1

Answer:

The double angle formulae for sin 2A, cos 2A and tan 2A

and this is our second double angle formula. Similarly tan(A + A) = tan A + tan A 1 − tanA tanA so that tan 2A = 2 tanA 1 − tan2 A These three double angle formulae should be learnt.