# Calculus - Tangent Line

posted by
**Andrew** on
.

Hi, im having problems with the following problem. The main issue is actually starting the problem.

Find the two points on the curve y = x^4 - 2x^2 - x that have a common tangent line.

First, find the derivative of y(x) so that you know the slope of the tangent line at any given x.

The derivative will be a quadratic formula for which there may be two solutions.