Question

2cos^2theta=1 then theata=

Answer 1

$2 { \cos }^{2} \alpha = 1 \\ { \cos }^{2} \alpha = \frac{1}{2} \\ \cos( \alpha ) \times \cos( \alpha ) = \frac{1}{2} \\ put \: \alpha = 45 \\ \frac{1}{ \sqrt{2} } \times \frac{1}{ \sqrt{2} } = \frac{1}{2} \\ \frac{1}{2} = \frac{1}{2} \\ \alpha = 45$

Answer 2

2cos²theta=1
cos²theta=1/2
costheta=√1/√2. (√1=1)
costheta=1/√2
theta =45