Use a sum or difference formula to find the exact value of the following. Sin 6 Pi/5 Cos 13 Pi/15 - Cos 6 Pi/5 Sin 13 Pi/15

The function y= x - 4x+ 5 approximates the height, y, of a bird, and its horizontal distance, x, as it flies from one fence post to another. all distances are in feet. complete the square to find and interpret the extreme value (vertex). select two answers: one extreme value and one interpretation.