## Calculus with Applications (10th Edition)

$$8\tan x + C$$
\eqalign{ & \int {8{{\sec }^2}} xdx \cr & {\text{use multiple constant rule }} \cr & = 8\int {{{\sec }^2}} xdx \cr & {\text{integrate by using the Basic Trigonometric integral }}\int {{{\sec }^2}x} dx = \tan x + C \cr & then \cr & = 8\tan x + C \cr}