Please answer the following questions will all the steps(Including graphs for question 2). Thank you!

1. Write down the nth Riemann sum for the following integrals. (a) r dr, for n = 4. 2 (b) sin (2x ) d.x for n = 6. 2. Use the geometric interpretation of definite integrals to evaluate the following. (a) (-4) d.x 3 (b) . (t - 5) dt