Can anyone answer and explain the question: Find the intervals on which x satisfies x^{2}+8x>0

Printable View

- April 9th 2013, 03:27 PMcraff25Need help on a problem *Urgent* please help
Can anyone answer and explain the question: Find the intervals on which x satisfies x

^{2}+8x>0 - April 9th 2013, 03:36 PMemakarovRe: Need help on a problem *Urgent* please help
Factor out x and use the fact that the product is positive iff both factors have the same sign.

- April 9th 2013, 03:39 PMcraff25Re: Need help on a problem *Urgent* please help
Is this the right answer? im unsure of what the correct answer format is

x<-8 makes expression positive

-8<x<0 makes expression negative

0<x makes expression positive - April 9th 2013, 03:40 PMcraff25Re: Need help on a problem *Urgent* please help
- April 9th 2013, 03:45 PMemakarovRe: Need help on a problem *Urgent* please help
Yes, this is the right answer. Since you only need to find when x

^{2}+ 8x > 0, the answer is x < -8 or x > 0. Alternatively, written as a union of intervals, x ∈ (-∞, -8) ∪ (0, ∞). - April 9th 2013, 03:49 PMcraff25Re: Need help on a problem *Urgent* please help
Thanks very informative and helpful!