Given `y=1/4x^2, y=2x^2, x+y=3, x>0`
Find the intersection point of `y=2x^2` and `y=-x+3.`
`2x^2=-x+3`
`2x^2+x-3=0`
`(2x+3)(x-1)=0`
`x=-3/2, x=1`
Ignore the x=-3/2. The original problem states that x>0.
When x=1, y=2. The intersection point is (1,2).
Find the intersection point of `y=-x+3` and `y=1/4x^2` .
`1/4x^2=-x+3`
`x^2+4x-12=0`
`(x+6)(x-2)=0`
`x=-6, x=2`
Ignore the x=-6. The original problem states that x^0.
When x=2, y=1. The intersection point is (2, 1).
`A=int_0^1(2x^2-1/4x^2)dx+int_1^2(-x+3-1/4x^2)dx`
`=int_0^1(7/4x^2)dx-int_1^2(1/4x^2+x-3)dx`
`=[7/4*x^3/3]_0^1-[1/4*x^3/3+x^2/2-3x]_1^2`
`=[7/12x^3]_0^1-[1/12x^3+x^2/2-3x]_1^2`
`=[7/12(1)^3-0]-[(1/12(2)^3+(2)^2/2-3(2))-(1/12(1)^3+(1)^2/2-3(1))]`
`=[7/12]-[8/12+2-6-1/12-1/2+3]`
`=[7/12]-[7/12-1/2-1]`
`=[1/2+1]`
`=3/2`
The area enclosed by the given curves is 3/2 units squared.
The black graph is `y=1/4x^2.`
The red graph is `y=2x^2.`
The green graph is `x+y=3=>y=-x+3.`
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