Question

prove that
2sin^2theta+2cos^2theta-1=0

Answer 1

$2\sin^2\theta + 2\cos^2\theta -1 = 2*(sin^2\theta + \cos^2\theta) - 1 = 2-1 =1$

for any value $\theta$

hence the assumption $2\sin^2\theta + 2\cos^2\theta -1 = 0$ is not true

Answer: The original hypothesis requiring proof is false