a.) Find a vector function that represents the curve of intersection between the cylinder x2 + z2 = 9 and the plane x + y + z = 1. b.) Consider the curve r(t) = (t, cos(t) , sin(t)) where 0 S t S 47. Carefully sketch the curve described by r(t) and its projections onto the coordinate axis. C.) Evaluate exactly: [" r(t)dt ifr(t) = (t, t cos(t) , t sin(t))