To find 15, Beau found 32 = 9 and 4 = 16. He said that since 15 is between 9 and 16,15 must be between 3 and 4. He thinks a good estimate for 15 is 3+4 = 3.5. Is Beau's estimate high, low, or correct? Explain.​

Use stokes' theorem to evaluate c f · dr where c is oriented counterclockwise as viewed from above. f(x, y, z) = xyi + 5zj + 7yk, c is the curve of intersection of the plane x + z = 8 and the cylinder x2 + y2 = 81.