algebra precalculus - Review of solved Pre-Calculus/Calculus questions (Range of subjects)

I really need some help. This has been driving me crazy for the past week! I've been working on this calculus sudoku and I cannot solve it, so I have come to the conclusion that I must have incorrectly answered at least one question. Are there any glaring mistakes here?

Thank you very much!

Answer

$7x^{\sin \pi}$ should be $7,$ rather than $1$.