Question

T
23) Verify that cos3A = 4 cos'A-3 COSA , for A = 30°​

Answer 1

Answer:

I don't know the answer sorry

Step-by-step explanation:

I don't know the answer sorry

Answer 2

A=30

cos3A=Acos^3-3cosA

cos3A=cos 90

cos90=4(cos30)^2 - 3(3cosA 30)

0=4.(root3/2)-(3.root 3/2)