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.

By Stokes' theorem,

where is the surface with as its boundary. The curl is

Parameterize by

with and . Then take the normal vector to to be

Then the line integral is equal to the surface integral,

1) is right

step-by-step explanation:

step-by-step explanation:

you can add the two numbers and divide the result by 2. or you can find the gap between the two numbers and add half of this to the smaller number.