00:01
In this question we are given z is equals to 9 minus x squared minus y square and f of x y z is equals to 6 z i cap plus 8 x j cap plus 4 y k cap.
00:20
Here in this question we have to find the integral over the curve.
00:25
So for this we put z is equal to 0.
00:28
So from here we have x squared plus y square equals to 9.
00:33
And here we put x is equals to 3 cost t and y is equals to 3 sine t, such that t is from 0 to 2 pi.
00:46
From this we can write the vector r, which is equals to 3 cost t, i cap plus 3 sine t, j cap, plus 0 k cap.
01:02
From here the differentiation of vector r is equals to minus 3 sine t i cap plus 3 cos t j cap.
01:14
And we can write the vector f of r t which is equals to 24 cost t j cap plus 12 sine t k gap and from here f of r this is if f f of r t dot product with r dash t is equals to 72 cost square t and from here we can write it as 72 1 plus cos of 2 t divided by 2 which is equals to 36 1 plus plus cos 2 t divided by 2 which is equals to 36 1 plus cos 2 t and from here we can find the integral over c of f .dr, which is equals to integral from 0 to 2 by 36 multiplied with 1 plus cost 2 t d t.
02:16
And from here, this value is equals to 36 t plus sine of 2t divided by 2 limits are from 0 to 2 pi...