Question

if teta=45 degree,verify that cos 2teta=2cos^2teta-1​

Answer 1

Answer:

Step-by-step explanation:

If theta = 45°,

Cos 2theta = cos 2(45°) = cos 90°= 0

And 2cos² theta -1 = 2( cos² 45°) -1

= 2 (1/√2) ² -1= 2(1/2) -1 = 1-1 = 0.

Hence both are equal