### Home > PC > Chapter 4 > Lesson 4.2.1 > Problem 4-74

4-74.

Given

*s*^{2}+*c*^{2}= 1, rewrite the following expressions using only*c*. Homework Help ✎*c*^{2}−*s*^{2}

Rewrite the given equation for *s*^{2}.

Then substitute in that expression.

4-74.

Given

*s*^{2}+*c*^{2}= 1, rewrite the following expressions using only*c*. Homework Help ✎*c*^{2}−*s*^{2}

Rewrite the given equation for *s*^{2}.

Then substitute in that expression.