### Home > CALC > Chapter Ch5 > Lesson 5.2.1 > Problem 5-57

5-57.

Since we cannot find the derivative (IROC), calculate the average rate of change.

For *e*(*t*):

Use Hana, Anah, or Hanah's method to approximate the rate of change for *T*(*e*) at *e* = 2750.

Use Hana, Anah, or Hanah's method to approximate the rate of change for *T*(*t*) at *t* = 120.