For the following exercises, find the quantities for the given equation. 1. Find dy at x = 1 and y = x + 3 if dx : 4. dt dx 2. Find at x = -2 and y = 2x + 1 if dy = 1. dt dz 3. Find dt at (x, y) = (1,3) and z = x + y if x = 4 and dx dt dy = 3. dt