SOLUTION: For each x>0, let m(x) be the slope of the line which goes through the point (0,0) and the point (x,y) on the curve y=(x^2)(e^(-0.25x)). What is the largest possible value for the

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Question 1052798: For each x>0, let m(x) be the slope of the line which goes through the point (0,0) and the point (x,y) on the curve y=(x^2)(e^(-0.25x)). What is the largest possible value for the m(x)?
note: it is e raised to (-0.25x)
Work: I believe I've taken the correct first derivative and second derivative of the curve using chain rule and product rule, But I don't know what the question is asking for or how to answer it. y=(x^2)(e^(-0.25x)) -> 1st derivative y'=2xe^((-1/4)x) + x^2((-1/4)(e^(-1/4)x)) -> 2nd derivative:
y''= 2(e^((-1/4)x) + 2x(e^((-1/4)x)(-1/4) + 2x((-1/4)e^((-1/4)x) + x^2((-1/16)(e^(-1/4)(x)))
If possible please check my derivatives, thanks in advance.

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
For each x>0, let m(x) be the slope of the line which goes through the point (0,0) and the point (x,y) on the curve y=(x^2)(e^(-0.25x)). What is the largest possible value for the m(x)?
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y= x%5E2%2Ae%5E%28-0.25x%29
y' = 2x%2Ae%5E%28-0.25x%29+-+%28x%5E2%2F4%29%2Ae%5E%28-0.25x%29
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y" =
y" =
y" = 2e%5E%28-0.25x%29+-+x%2Ae%5E%28-0.25x%29+%2B+%28x%5E2%2F16%29%2Ae%5E%28-0.25x%29
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Set y" = 0
2e%5E%28-0.25x%29+-+x%2Ae%5E%28-0.25x%29+%2B+%28x%5E2%2F16%29%2Ae%5E%28-0.25x%29+=+0
32e%5E%28-0.25x%29+-+16x%2Ae%5E%28-0.25x%29+%2B+x%5E2%2Ae%5E%28-0.25x%29+=+0
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e%5E%28-0.25x%29+=+0 Ignore
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Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc)
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case 1x%5E2%2B-16x%2B32+=+0) has the following solutons:

x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca

For these solutions to exist, the discriminant b%5E2-4ac should not be a negative number.

First, we need to compute the discriminant b%5E2-4ac: b%5E2-4ac=%28-16%29%5E2-4%2A1%2A32=128.

Discriminant d=128 is greater than zero. That means that there are two solutions: +x%5B12%5D+=+%28--16%2B-sqrt%28+128+%29%29%2F2%5Ca.

x%5B1%5D+=+%28-%28-16%29%2Bsqrt%28+128+%29%29%2F2%5C1+=+13.6568542494924
x%5B2%5D+=+%28-%28-16%29-sqrt%28+128+%29%29%2F2%5C1+=+2.34314575050762

Quadratic expression 1x%5E2%2B-16x%2B32 can be factored:
1x%5E2%2B-16x%2B32+=+%28x-13.6568542494924%29%2A%28x-2.34314575050762%29
Again, the answer is: 13.6568542494924, 2.34314575050762. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+1%2Ax%5E2%2B-16%2Ax%2B32+%29

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