Given that sin(a) = 1/3 and cos(b)= -2/6 with a and b both in the interval [?/2, ?]find the exact values of sin(a + b) and cos(a ? b).Step 1: Since sin(a)= 1/3 and a in the interval [?/2, ?]cos(a)Step 2: Since cos(b) = -2/6 and b in the interval [and b in the interval/2, and b in the interval]Step 3: cos(a - b) =