A machine is subjected to the motion x(1) = A cos(50t + a) mm. The initial conditions are given by x(0) = 3 mm and x(0)= 1.0 m/s. a. Find the constants A and a. b. Express the motion in the form x(t) = A₁ cos wt + A₂ sin wt, and identify the constants A₁ and A₂.