### Home > CALC > Chapter 4 > Lesson 4.1.1 > Problem 4-8

4-8.

For each function, find its slope function,

*f*′(*x*). Homework Help ✎*f*(*x*) = 6 cos*x*

Power Rule.

Before you differentiate, rewrite *f*(*x*) with a fractional exponent.

Will *f* '(*x*) be positive or negative?

Before you differentiate, factor the numerator and simplify. THINK: Will the derivative need a restricted domain? Why or why not?