Calculus/Integrals

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Question
Let R be the region bounded by the parabola y=x-x^2 and the x-axis. Find the equation of the line y=mx that divided this region into two regions of equal area.

Answer
The parabola intersects the x-axis at x=0 and x=1.
The area is integral(x-x^2,x=0..1)=1/6
Now we seek a line of the form y=mx so that
integral(x-x^2-mx,x=0..a)=1/12, where x=a is where the
parabola and line intersect again after x=0...which is
where x-x^2=mx ==> x=1-m.  Thus, we need to solve for 'm'
so that integral(x-x^2-mx,x=0..1-m)=1/12...which yields
(1/6)(1-m)^3=1/12 ==> m=1-2^(-1/3)

Calculus

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Abe Mantell

Expertise

Hello, I am a college professor of mathematics and regularly teach all levels from elementary mathematics through differential equations, and would be happy to assist anyone with such questions!

Experience

Over 15 years teaching at the college level.

Organizations
NCTM, NYSMATYC, AMATYC, MAA, NYSUT, AFT.

Education/Credentials
B.S. in Mathematics from Rensselaer Polytechnic Institute
M.S. (and A.B.D.) in Applied Mathematics from SUNY @ Stony Brook

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