Answer
See below.
Work Step by Step
Let $f(x)=\sqrt x$ and $g(x)=1-x^2$
Then $H(x)=f(g(x))=f(1-x^2)=\sqrt{(1-x^2)}$.
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.