Why are you switching names ??
find the intersection;
from the first:
x = 3 - 3y
into the 2nd:
y^2 - (3-3y) = 1
y^2 + 3y - 4 = 0
(y+4)(y-1) = 0
y = -4 or y = 1
in x = 3-3y ....
if y = 1, x = 0 ---->(0,1)
if y = -4 , x = 15 , ---> (15, -4)
Your sketch should look like this and my answers are confirmed
http://www.wolframalpha.com/input/?i=plot+3y%2Bx%3D3+%2C+y%5E2-x%3D1
judging from the graph I would integrate with respect to y
so the effective width of my horizontal slice
= 3-3y - (y^2 - 1)
= 4 - 3y - y^2
area = ∫(4 - 3y - y^2) dy from -4 to 1
= (4y - (3/2)y^2 - (1/3)y^3) | from -4 to 1
= (4 - 3/2 - 1/3) - (-16 -24 + 64/3)
= 13/6 - (-56/3)
= 125/6
Sketch the region enclosed by the given curves. Decide whether to integrate with respect to x or y. Then find the area of the region.
3y+x=3 , y^2-x=1
1 answer