How to solve this question by using trigonometric identities?Pls help!!thanks orz

What is the average rate of change for this function for the interval from x=2 to x=4 ?

Ricky takes out a $31,800 student loan to pay his expenses while he is in college. after graduation, he will begin making payments of $190.66 per month for the next 30 years to pay off the loan. how much more will ricky end up paying for the loan than the original value of $31,800? ricky will end up paying $ more than he borrowed to pay off the loan.

Two angles are complementary. the large angle is 36 more than the smaller angle. what is the measure of the large angle?