So I'm frustrated with this problem:Evaluate the line integral c 5xy2ds , where C is the right half of the circle x2+y2=36
So far, I've taken x=6Cos(t) and y = 6Sin(t) to parametrize a circle with radius of 6, then taken their modulus (to get rid of ds and get dt) and got 6 because rest of it cancels out..
After that I replaced the xy2 with the trig. values to get 5*6*Cos(t)Sin2(t). After that when I integrate it with respect to t, 3Pi/2 < t < Pi/2 to go over only the right side of the circle, I'm getting 20, which is wrong because the browser is rejecting it as the wrong answer.. :/
I think I'm doing something really silly. Anyone wanna help?
Gosh! totally screwed that one didn't I? Thankfully I have unlimited tries for this one...
Okay So I tried it with 720 Cos(t)Sin^2(t), but still the wrong answer..
Also, (at the risk of sounding stupid), I did it with 1080Cos(t)Sin^2(t) because 30*36 = 1080..
But still no luck.. Thank you so much for your help though..