Question

1+ cos2x =
2/1+tan ²x

Answer 1

sure but 1st show every1 wut u know

Answer 2

Use the Pythagorean identity to rewrite the tangent:

`\frac2{1+\tan^2x}=\frac2{\sec^2x}=2\cos^2x`

Then use the double angle identity for cosine:

`\cos^2x=\frac{1+\cos(2x)}2`

`\implies2\cos^2x=1+\cos(2x)`

and the identity is proved.