Answer
$$2$$
Work Step by Step
$$
\log _{b^{2}}\left(b^{4}\right)=\log _{b^{2}}\left(b^{2}\right)^2=2\log _{b^{2}}\left(b^{2}\right)=2(1)=2.
$$
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.