Parametric & implicit differentiation

In this lesson you'll learn two clever ways to find dy by dx when a curve is not written simply as y equals something. You'll differentiate parametric equations, where x and y each come from a parameter t, using dy/dx = (dy/dt)/(dx/dt). You'll differentiate implicit equations, where x and y are tangled together, remembering the all-important dy/dx factor and the product rule. You'll find gradients at given points, locate horizontal tangents, and write the equation of a tangent line.