This expression is equal to, and I'm going to arbitrarily switch colors just because the green is getting monotonous, pi times 1 squared over 2 minus 0 squared over 2. I could write it squared. 1 squared over 2 minus 0 squared over 2 minus pi times 1 to the third over 3 minus 0 to the third over 3. And so we get this is equal to, let me do it in that same blue color, it's equal to, so this is just simplified, this is just 0 right over here. This is 1 squared over 2, which is just 1 half. So it's just pi over 2, 1 half times pi minus, well this is just 0, this is 1 third minus pi over 3. Minus pi over 3 and then to simplify this it's just really subtracting fractions.