3. (20%) Let x = [-x7,x2,...,x,) and y = [y, Y2 ..., y] be two vectors (one-dimensional arrays). The inner product of x and y is a scalar and is given by P = x,y; + xy + ... + x, y, a) Express the inner product P using the (summation) notation. b) Determine an explicit formula for evaluating Pif x = i and y, = i, i=1,2,...n. Show your work to receive full credit