Answer:
y" = csc(x)[9cot²(x) - csc²(x)]
Explanation:
Step 1: Define
y = 9csc(x)
Step 2: Find 1st derivative
y' = -9csc(x)cot(x)
Step 3: Find 2nd derivative
y" = 9csc(x)cot(x)cot(x) + -csc(x)csc²(x)
y" = 9csc(x)cot²(x) - csc³(x)
y" = csc(x)[9cot²(x) - csc²(x)]