ok so for the function f(x) = (x^(3/5))(x^(2)-13) (the many parentheses are to make it clear) i am supposed to find f'(x) and the intervals in which f(x) is decreasing

**and** increasing

**<=== impossible **
i found f'(x) = (13/5)(x^(-2/5))(x^(2)-3)

**<=== OK**
i think this is correct

but then to find the increasing and decreasing intervals i got it wrong

i started with the increasing interval and got x>sqrt3

**<=== OK**
and -sqrt3>x>0,

**<=== impossible: Here you state that**
i keep doing it over and over but i dont understand where its wrong