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# Area between two curves ? watch

1. Find the area of the region enclosed by the curves with equations y=x^2-16 and y=4x-x^2?

I know you find the points of intersection first but then i'm stuck could anyone pleaseeeee help me ?
2. Might help you to draw a diagram, and then break it down into areas which you know how to calculate.
3. The area between two curves is the same as the area between the difference of the two curves and the x-axis. [If it's negative, get rid of the minus sign.]

So for example the area between and between 0 and is .
4. Make them equal each other so you have one equation in terms of x.

Find x (2 values).

Integrate the first minus the second and use the x values you just found for the limits.
5. i'm still stuck on this
6. Cleavage
7. how do you find the points of intersection
8. find intersection points (-2,4)
plot on graph make it visible where R is. Integration of upper curve minus lower curve integral. Using the intersection points as limits
9. y=x^2-16 and y=4x-x^2

x^2-16=4x-x^2

solve for x
10. ive tried that i keep getting the wrong answer
11. You may have to use the quadratic forumla, and you will get 2 intersection points
which are roughly 6.472 and -2.472

Those are the x values, so you use the definite intergral of (x^2-16)-(4x-x^2) between 6.472 and -2.472 to get the area
12. (Original post by moesizlak)
ive tried that i keep getting the wrong answer
show what you have done and someone will be able to point out your error

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Updated: March 28, 2011
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