#### Question

Prove that:

\[\cos^2 \theta\left( 1 + \tan^2 \theta \right) = 1\]

#### Solution

cos^{2}θ (1 + tan^{2}θ)

= cos^{2}θ × sec^{2}θ

= cos^{2}θ ×`1/(cos^2 theta)`

= 1

Is there an error in this question or solution?

Solution Prove That: Cos 2 θ ( 1 + Tan 2 θ ) = 1 Concept: Application of Trigonometry.