Write the trigonometric expression in terms of sine and cosine, and then simplify.
cos2(θ) (1 + tan2(θ))
cos 2θ ( 1 + tan 2θ) =
cos 2θ ( 1 + sin 2θ / cos 2θ ) =
cos2θ + sin 2θ
cos^2 θ - sin^2 θ + 2sinθcosθ
its coming up wrong when i type that in:(
The problem might be that there are many ways to express cos2θ + sin2θ
You might also try these
1 - 2sin^2 θ + 2sinθcosθ
2 cos^2θ - 1 + 2sinθcosθ
+318 
