00:01
For this problem, we are asked to evaluate the line integral of 2x2 times x plus yi plus y .j.
00:09
.dr over the smooth curve from negative 1 to the point 3 .2, using the fundamental theorem of line integrals.
00:17
So we want to find some function f such that the gradient of f equals our function, or our vector function, 2x plus y, 2x plus y, 2x plus y.
00:31
So integrating the x component of our gradient with respect to x, we'll have that f must be equal to 2x, or i'll write it as we'd have 2x squared over 2, giving us an x squared, plus 2 times y times x, plus some unknown function, g of y.
00:54
Then taking the partial derivative of this with respect to y, we have 2x plus g of y must be equal to 2 times x plus, well, i'll expand out that bracket.
01:08
It would be 2 times x plus 2 times y...