etotheix
- 21
- 0
Homework Statement
Evaluate the following line integral on the indicated curve C
\int(y^2-x^2)ds
C: x = 3t(1+t), y=t^3 ; 0 <= t <= 2
Homework Equations
ds = \sqrt{(f'(t))^2+(g'(t))^2}dt
The Attempt at a Solution
dx/dt = 3+6t
dy/dt = 3t^2
ds = \sqrt{(3+6t)^2+(3t^2)^2}dt
ds = 3*\sqrt{t^4+4t^2+4t+1}dt
y^2 = t^6
x^2 = (3t+3t^2)^2 = 9t^2+18t^3+9t^4
\int(y^2-x^2)ds = 3\int(t^6-9t^2-18t^3-9t^4)\sqrt{t^4+4t^2+4t+1}dt
From here I don't know how to solve the integral, and it looks way more complicated than what we have done so far in class. Maybe I am doing something wrong? Or there is a trick involved here? Any help would be greatly appreciated. Thanks.
Last edited: