POLQ 2 | Lesson 3 | Practice (Solving Radical Equations)

Try the following radical equations. Make sure to check each solution to be sure it makes the original equation true.

a) \( \sqrt{x} =7 \)

b) \( \sqrt{x} =-7 \)

c) \( \sqrt[3]{x} =7 \)

d) \( \sqrt[3]{x} =-7 \)

e)\(\sqrt{x} -1 = \sqrt{x}\)

f)  \(\sqrt{x-15} = \sqrt{x} – 3\)

The solutions that did not “work” are called extraneous solutions.

Notice that in b the right hand side of the equation is positive, you are taking the positive square root of x.  Why does d have a solution and b does not?

Check your solutions. 

Go to Watch (Solving Radical Equations)