I need help please help out

Hillel is juggling flaming torches to raise money for charity. his initial appearance raises $500\$500 $500 , and he raises $15\$15 $15 for each minute of juggling performance. the amount rr r of money hillel raises is a function of tt t , the length of his performance in minutes. write the function's formula.

Can someone check if i did this correct. it’s number 4 if you’re wondering.

What is the frequency of the sinusoidal graph?