is this 3u (1 Viewer)

[ekjchale#1]

although theyve given x=sintheta, the way i did it which i assume is the only way requires u to sub in u=costheta afterwards as well and theyve not given that. so is this a common thing they do in 3u?

 

[Drongoski]

Avoiding formal substitution:

 

[Undefined]

You don't need to use u sub to integrate sin(theta)cos(theta)^2. The first on the formula sheet for integral calculus is when f'(x) (-sinx) is next to f(x) (cosx) to the power of n (2).

In fact, they didn't even need to give you the u sub. [Edit: if they didn't give you the u sub] you could've done it straight off the bat with f'(x) being 2x, f(x)=1-x^2, n=1/2

 

[ekjchale#1]

You don't need to use u sub to integrate sin(theta)cos(theta)^2. The first on the formula sheet for integral calculus is when f'(x) (-sinx) is next to f(x) (cosx) to the power of n (2).

In fact, they didn't even need to give you the u sub. You could've done it straight off the bat with f'(x) being 2x, f(x)=1-x^2, n=1/2

Yep I understand U sub was not required indeed I agree it wud be way easier normally but the fact they gave a thing to sub made me think that it only wants U to use U sub in it.

 

[Undefined]

Ye, I should've clarified that - if they give you a u sub you have to use it. Thanks for picking up on that