Answer: LHS simplifies to RHS, as shown below.
\[\sec\theta+\tan\theta=\frac{1+\sin\theta}{\cos\theta}\]
\[\text{LHS}=\frac{(1+\sin\theta)(1-\sin\theta)}{\cos\theta}=\frac{1-\sin^2\theta}{\cos\theta}\]
\[=\frac{\cos^2\theta}{\cos\theta}=\cos\theta=\text{RHS}\]