Solve the following problems, providing detailed steps wherever required:
1. Evaluate the iterated integral 1∫e0∫1 (x/x+y) dydx.
2. Let R = {(x, y): 0 ≤ x ≤ π, 0 ≤ y ≤ a}. Find the values of a, with 0 ≤ a ≤ π, for which ∫∫Rsin(x + y) dA is equal to 1?
3. Sketch the region of integration and evaluate the integral 0∫4-√(16-y2)∫√(16-y2)2xydxdy.
4. Evaluate the integral -2∫2x2∫3-x2 xdydx.
5. Evaluate the integral ∫∫R y2 dA; R is bounded by x = 1, y = 2x + 2, and y = - x - 1.
6. Find the volume of the solid region for the solid S between the surfaces z = ex-y and z = -ex-y, where S intersects the xy plane in the region R = {(x, y): 0 ≤ x ≤ y, 0 ≤ y ≤ 1}.
7. Reverse the order of integration in the integral 0∫2x2∫2xf(x, y)dydx.
8. Use a double integral to compute the area of the region bounded by the lines x = 0, x = 4, y = x, and y = 2x + 1. Also, make a sketch of the region.
9. Find the volume of the solid below the paraboloid z = 4 - x2 - y2 and above the region R = {(r, θ): 1 ≤ r ≤ 2, - π/2 ≤ θ ≤ π/2}.
10. Sketch the given region of integration R and evaluate the integral over R using polar coordinates
∫∫R1/√(16-x2-y2) dA;
11. Sketch the region inside the lobe of the lemniscate r2 = 2 sin2θ in the first quadrant. Also, express ∫∫Rf(r, θ) dA as an iterated integral over R.
12. Sketch the region inside both the cardioid r = 1 + sin θ and the cardioid r = 1 + cos θ. Also, use integration to find its area.
13. Evaluate the integral 0∫π/21∫∞(cosθ/r3)rdrdθ.
14. Evaluate the integral -2∫21∫21∫e(xy2/x)dzdxdy.
15. Evaluate the integral 0∫π0∫π0∫sinx sinydzdxdy.
16. Find the volume of the solid region bounded by the parabolic cylinder y = x2 and the planes z = 3 - y and z = 0.
17. Find the average value in case of average temperature in the box D = {(x, y, z): 0 ≤ x ≤ ln2, 0 ≤ y ≤ ln4, 0 ≤ z ≤ ln8}, with a temperature distribution of T(x, y, z) = 100e-x-y-z.
18. Two different tetrahedrons fill the region in the first octant bounded by the coordinate planes and the plane x + y + z = 4. Both solids have densities that vary in the z-direction between ρ = 4 and ρ = 8, according to the functions ρ1 = 8 - z and ρ2 = 4 + z. Find the mass of each solid.