Question

What is the surface area produced by rotating `f(x)=sinx/cosx, x in [0,pi/4]` around the x-axis?

Answer 1

Curved-surface cone , with vertex at the origin and base unit circle generated by the rotation of the terminal point of the curve `(pi/4, 1)` about the axis y = 0.

Explanation:

In nature, similar vertical pyramids are created by lava, from volcanic eruptions.