x^4-x<0

How do I solve it?

Printable View

- Jul 25th 2011, 03:15 PMRK29Inequality with higher degree
x^4-x<0

How do I solve it? - Jul 25th 2011, 03:21 PMpickslidesRe: Inequality with higher degree
Have you tried to factor the LHS yet?

- Jul 25th 2011, 03:23 PMRK29Re: Inequality with higher degree
I tried doing X(X^3 -1) <0 then x=0 x^3-1=0 didn't work when i checked using solution

- Jul 25th 2011, 03:28 PMpickslidesRe: Inequality with higher degree
Maybe you can factor further?

Hint:

Sketching the graph of will help after you have found the zeros. - Jul 25th 2011, 03:40 PMPlatoRe: Inequality with higher degree
- Jul 25th 2011, 03:48 PMArchie MeadeRe: Inequality with higher degree
- Jul 25th 2011, 03:58 PMAlso sprach ZarathustraRe: Inequality with higher degree
- Jul 25th 2011, 04:54 PMskeeterRe: Inequality with higher degree

note that the factor for all x (how can you check that the factor is always positive?)

for the other two factors that can equal zero ... critical values are x = 0 and x = 1

these two critical values divide the x-value number line into three regions ...

x < 0 , 0 < x < 1 , and x > 0

test a single x-value from each of the above intervals into the original inequality to see if this value makes the inequality true or false ...

if true, then all values of x in that interval make the inequality true ... if false, then otherwise. - Jul 25th 2011, 05:41 PMtheloserRe: Inequality with higher degree

This works as well just remember to put the strict inequity back in the answer.