Sunday

April 20, 2014

April 20, 2014

Posted by **Giselle** on Monday, February 14, 2011 at 10:32pm.

x^3-5x^2-14x<0

- Pre Calc -
**Reiny**, Monday, February 14, 2011 at 11:53pmx^3-5x^2-14x<0

x(x^2 - 5x - 14) < 0

x(x-7)(x+2) < 0

so we have 3 critical values:

x = 0, -2, and 7

investigate each domain

1. x < -2 , I will pick x = -5

(-)(-)(-) which is < 0 , that works

2. between -2 and 0, I will pick x = -1

(-)(-1)(+) > 0 , no good

3. between 0 and 7, I will pick x = 1

(+)(-)(+) < 0 , yup, that works

4. x > 7, I will pick x = 10

(+)(+)(+) > 0 , no good

so x < -2 OR 0 < x < 7

notice I did not actually have to find the algebraic answer, just determine if the result is + or -

- Pre Calc -
**Giselle**, Tuesday, February 15, 2011 at 7:50amthanks!

**Related Questions**

Pre Calc - Solve the non-linear inequality: x^3-5x^2-14x<0

pre calc - solve each inequality: (x-4)(x-2)^2(x-3)^2 < 0

Pre-Algebra - Solving it would give u x = -4...but I am not sure how you would ...

pre-algebra - can someone check if this inequality is solve right 5x + 3 >= ...

pre-algebra - Solve the inequality- j-7<24 8+b<-3 h/4>16 Treat the ...

pre-calc - How do you solve this inequality? 2x over 4 minus 5x+1 over 3 is ...

8th grade math - how would i graph this inequality? 14x-23<5x+13

math - I am doing something wrong when I work this question. Can someone show me...

math - I need help solving this non-linear inequality:6x^2>6+5x

Algebra 2(check) cont.. - 1)solve the inequality -3(r-11)+15>_9 my answer = r...