7. (a) Use Newton's method ONCE with an initial guess of co = 1 to find an approxi- mation to the solution of the equation a = cos (5x) - 573. (Newton's method for solving f(2) = 0: $41 = 1, - f(In ) for n = 0, 1, 2, ... ) (4 marks) (b) The period T of a pendulum is related to its length ( by 72 = k. where k is a constant. If { is increased by 2%, use calculus to determine the approximate percentage change in T