English Deutsch Français Italiano Español Português 繁體中文 Bahasa Indonesia Tiếng Việt ภาษาไทย
All categories

the three im stuck on are
(x-2)(3-x)>0
x^4-1<0
(x-2)/(x-3)>or equals to 0

PLEASE HELP!!!

2007-08-23 15:02:42 · 3 answers · asked by Anonymous in Science & Mathematics Mathematics

3 answers

Let's look at your first problem this way: a product of the factors x - 2 and 3 - x is positive if and only if both factors have the same sign. Therefore, either

(1) x - 2 > 0 and 3 - x > 0 , or

(2) x - 2 < 0 and 3 - x < 0 .

(1) requires that x > 2 AND 3 > x; that is, 2 < x < 3. On the other hand, (2) requires that x < 2 AND 3 < x. Clearly it is not possible that x is less than 2 and greater than 3 at the same time, so (2) cannot be satisfied.

The only solution is 2 < x < 3.

Your second problem can be analyzed by factoring x^4 - 1. We find x^4 - 1 = (x + 1)*(x - 1)*(x^2 + 1) < 0. The product of three factors is negative if ond only if (3) all three factors are negative or (4) two are positive and one is negative. Clearly, case (3) is not possible since x^2 + 1 is never negative. Case (4) requires three subcases:
(a) x + 1 < 0 and the other two are positive, (b) x - 1 < 0 and others are > 0, and
(c) x^2 + 1 < 0 (which is impossible).

Hope you got the idea.

2007-08-23 15:42:44 · answer #1 · answered by Tony 7 · 0 0

3>x>2 for the first one
x>1^1/4 for the second one
x>3 for the third one

2007-08-23 15:15:38 · answer #2 · answered by Confused about life 2 · 0 0

x > –3 once you notice this type of situation on a attempt, it in many situations is there to work out in case you be useful to opposite the inequality sign once you have a step related to multiplication or branch with a unfavourable style. So be on the look-out for this type of step. certainly, maximum math finding out questions have a trademark to look for, like this one, so an help to doing nicely on tests is to be taught those besides because of the fact the recommendations themselves. whether, in case you do not sign up this "trick" nicely and inequality questions hammer your rankings, then do them like this: 4 – 6x < 22 4 – 6x + 6x < 22 + 6x 4 < 22 + 6x 4 – 22 < 22 + 6x – 22 –18 < 6x –18/6 < 6x/6 –3 < x and you on no account could desire to try this step in any respect. And in case you sense you purely could desire to state the respond with "x" first, it extremely is obtrusive and effortless to work out that "–3 < x" ability "x > –3" so even in spite of the indisputable fact which you employ the technique to shine your answer, you at the instant are not extremely responsive to it, you're merely employing sparkling good judgment. finally, to "invoice" and his lame crack from "Benchwarmers" — "maths" is very surprising. And so "Englishes" could be exhibiting lack of know-how, not exhibiting lack of know-how up. in case you be responsive to your Englishes invoice, you be responsive to there's a difference there...

2016-10-03 03:55:38 · answer #3 · answered by Anonymous · 0 0

fedest.com, questions and answers