isAlways: what did I do wrong?

Hi,

I have a somewhat complicate function of only 1 variable. When I plot it from the range [1, 10], it's clear that the function is always negative. However, when I use isAlways (with appropriate assumptions on the domain of the function), it gives me an unknown (unable to prove). Please find the sample code below. Seems like you'd need R2012 for assumeAlso to work.

Thanks a lot!

clear;

syms x real

W2 = 2*((25*(3*x - 30))/(11*(25*x - 8)^2) - 3/(11*(25*x - 8)) + 75/(25*x - 8)^2)*((3*x - 30)/(11*(25*x - 8)) + 3/(25*x - 8) - 1/11) - 2*((25*(3*x - 27))/(11*(25*x + 17)^2) - 3/(11*(25*x + 17)))*((3*x - 27)/(11*(25*x + 17)) - 1/11);

assumeAlso(x >= 1);
assumeAlso(x < 10);

fW2 = inline(char(W2));
fplot(fW2, [1, 10]);

isAlways(W2 < 0, 'Unknown', 'error');

[Art]

Nevermind... got it, I think. After I did

W2 = simple(W2);

And do the same thing, it gives me the answer.

Thanks!