# Thread: Evaluate triangular region...

1. ## Evaluate triangular region...

∫∫y^3 dA, where D is the triangular region with vertices
D
(0,0),(3,1) and (-2,5).
thankyou!

2. Make a sketch, that's all, only then you'll be able to set up the double integral.

3. i understand, but the problem was that i was confused in how to set up the double integral. thankyou.

4. Do i need to seperate into two different integrals?

5. Yes: $I=\int_{-2}^{0}\int_{f_1(x)}^{f_2(x)}y^3 dydx+\int_{0}^{3}\int_{f_3(x)}^{f_2(x)}y^3 dydx$

where $f_1, f_2, f_3$ are just the equations of the lines making up the triangle. You can figure out which line is what right?