statistics/calculus
posted by John .
e^(10)e^(10x)x/(e^(10)11)=0.25
and
e^(10)e^(10x)x/(e^(10)11)=0.75
Solve both for x.
Can you solve both of these for x without a Ti89 calculator? If so how?
The reason I want to calculate this is to find upper and lower quartiles of a deformity angle which is defined by the function on the left hand side of the equals sign.

You can certainly solve for x without a TI89, but you will need to use some kind of iterative method.
Judging by the shape of the curve, Newton's method should converge quite rapidly.