SOLUTION: Solve {{{x^3+2x^2-11x-12<0}}}

Algebra.Com
Question 135536: Solve
Answer by jim_thompson5910(35256)   (Show Source): You can put this solution on YOUR website!
Set the left side equal to zero.


When we use a graphing calculator, we find that the solutions are , and . So that means that the inequality factors to




Now plot the critical values on a number line





So let's evaluate a point that is to the left of (which is the left most endpoint). Let's evaluate the value

Start with the given inequality

Plug in

Evaluate and simplify



Since is true, this means that one part of the solution in interval notation is
-----------------------------------------------


Now let's test a point that is in between the critical values and


Start with the given inequality

Plug in

Evaluate and simplify


Since is false, this means that the interval does not work. So that means that this interval is not in the solution set and can be ignored.
-----------------------------------------------


Now let's test a point that is in between the critical values and


Start with the given inequality

Plug in

Evaluate and simplify



Since is true, this means that one part of the solution in interval notation is
-----------------------------------------------


So let's evaluate a point that is to the right of (which is the right most endpoint). Let's evaluate the value

Start with the given inequality

Plug in

Evaluate and simplify


Since is false, this means that the interval does not work. So that means that this interval is not in the solution set and can be ignored.
-----------------------------------------------

Answer:
So the solution set in interval notation is

RELATED QUESTIONS

factor x^3 + 2x^2 - 11x - 12 Thank... (answered by richwmiller)
Solve: 0 = x^3 - x^2 - 11x - 10 (answered by stanbon)
factor 2x^4 + 5x^3 - 11x^2 + 12 =... (answered by richwmiller)
solve... (answered by stanbon,Fombitz)
(2x^2+11x+12)/(x+4) (answered by ewatrrr)
-6x^3-11x^2+2x=0 (answered by jsmallt9)
How do you solve 2x/x-3 + x/x-8 = 3/x^2-11x+24? (answered by stanbon)
Can someone help me with this? Solve the inequality algebraically:... (answered by ikleyn)
Solve using the quadratic formula:... (answered by ewatrrr,rfer,shree840)