It was 3 instead of root 3 but idk how
What the formula for the mean function?
Chat GTP calls the cos thing the product to sum rule
The integral of 0 is C
Two methods.
Method 1: using substitution and getting it as 1- u ^2
Method 2: using standard results and getting the coefficient of x^2 = -1
Simple smaller substitutions to save time, making use of formula sheet
Using first principles wastes too much time