3. A rectangle has a perimeter of 42 feet. Its length, L, is three feet more than twice its width, W.
(c) create an equation in terms of L and W for the perimeter of the rectangle

The input to the function is x and the output is y. write the function such that x can be a vector (use element-by-element operations). a) use the function to calculate y(-1.5) and y(5). b) use the function to make a plot of the function y(x) for -2 ≤ x ≤ 6.