00:01
So first of all, according to the question, the value of f vector is x i cap plus y j cap plus z k cap.
00:11
Okay.
00:11
And the equation is x square plus y square is equal to 25 for the plane x plus y plus z is equal to three of x plus y plus z is equal to six.
00:28
Okay.
00:28
So for for oriented or oriented away from z axis away from z axis, we can neglect the z coordinate.
00:43
And in the polar coordinates, we will assume here x is equal to r cos theta, and y is equal to r sine theta.
00:49
Okay, so now, if we find the value of x square plus y square, it will be r square multiplied by sine square theta plus cos square theta, that will be one.
00:59
Okay, so it's value is 25.
01:02
That implies the value of r will be five.
01:05
Okay, so now if we find the value of d a vector, okay, so it will be equal to five cos theta i cap plus five sine theta j cap and the k cap coordinate will be neglected because we have oriented away from z axis okay, multiplied by dz d theta.
01:28
Okay, so now if we find the value of f vector in polar coordinates, it will be equal to five cos theta i cap plus five sine theta j cap here also the k cap coordinate will be neglected.
01:40
Okay, so if we find the value of f vector dot d a vector, so the similar similar coefficients like i cap and j cap will be multiplied individually.
01:51
Okay, so five multiplied by five is 25 and cos square theta plus 25 there will be sine square theta.
02:01
Okay, and this will be multiplied by dz d theta...