Answer
$=sec^{2}(\theta)tan(\theta)+sec^{3}(\theta)$
Work Step by Step
Use the product rule: $(f(x)g(x))'=f'(x)g(x)+f(x)g'(x))$
$(sec(\theta)tan(\theta)=(sec(\theta))'tan(\theta)+sec(\theta)(tan(\theta))'=sec^{2}(\theta)tan(\theta)+sec^{3}(\theta)$