Find f. (x>0) f ''(x) = x^-2
x > 0
f(1) = 0
f(5) = 0
i am having trouble finding f(x) because the denominator goes to infinity...
$\displaystyle f'(x) = \frac{x^{2}}{2} - 2x + C $
$\displaystyle f(x) = \frac{x^{3}}{6} - x^{2} + Cx + D $
$\displaystyle f(1) = 0 = \frac{1}{6} -1 + C + D $
$\displaystyle f(5) = 0 = \frac{125}{6} - 25 + 5C + D $
now just solve the above two equations simultaneously to find the values of C and D