There are many videos on Khan Academy on this topic. You can find an expanded list here.
The videos assigned for class are below.
- Intro to square-root equations and extraneous solutions (11:09) Solve .
- Solving square root equations: one solution (3:10) Solve .
- Solving square root equations: two solutions (5:28) Solve .
- Solving square root equations: no solutions (3:58) Solve .
- Extraneous solutions of radical equations (4:56) Find which values of make an extraneous solution for the equation .
- Solving cube root equations (3:34) Solve for given
- Domain of a radical equation (1:48) Find the domain of