Attempt following question by selecting a choice to answer.
e
Choose a formula that corresponds to the value of
cos 4θ.ee eeA.
e 2cos
2(2θ) - 1
B.
e 2cos
2(2θ) + 1
C.
e 1 + 2sin
22θ
D.
e 2cos 2θ
e
A
Step 1: cos 4θ = cos 2(2θ)[Using cos 2A = 2cos2A - 1.]
Step 2: = 2cos2(2θ) - 1