Negative 4 decreased by the product of two and a number squared

A figure is located at A(0, 0), B(−3, −4), and C(−3, 0) on a coordinate plane.

This form a right triangle ( because vector AC(3, 0) is perpendicular with vector BC(0, 4) at C. You can check it by take multiplication of vector AC and BC, you would get: vector AC x vector BC = 3 x 0 + 0 x 4 = 0)

And as you know a cone is created by rotating a right triangle around its side (not hypotenuse). Here, the right triangle ABC has AB as hypotenuse and AB is not lying on rotating axis (x axis).

=> The 3D-shape, which is created by rotating ABC around x-axis would be a cone.

Hope this helps!

:)