6]\": A. Write the equation of the line tangent to f(x) at x = 15. (3 points) 1. Given that f(x)=arctanx and g(x)=e \fC. Find the area enclosed by the x-axis, the function g(x), and the vertical lines x = 2 and x = 4. (4 points) D. Find the area enclosed by the x-axis, the function f"(x), and the vertical lines x = 0 and x =-. (4 points) 3