### Home > CALC > Chapter Ch3 > Lesson 3.3.1 > Problem 3-93

3-93.

If *f *′(*x*) = 3*x*^{2} + 2*x – *5, find a possible function for *f*(*x*). Then find another possible function. Homework Help ✎

Undo the power rule.

The 3x² in *f* '(*x*) will become *x*³ in *f*(*x*). What will happen to the 2*x* and the −5?

The 2*x* in *f* '(*x*) will become *x*² in *f*(*x*).

The −5 in *f* '(*x*)will become −5*x* in *f*(*x*).

Giving us *f*(*x*) = *x*³ + *x*² − 5*x*. But there are other functions that also have the same derivative.

To find another *f*(*x*), think about the Power Rule. What happens to a constant when you differentiate?