SOLUTION: f is define as follows: f(x)=x(x+1) solve the inequality f(x) >6

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Question 1087116: f is define as follows: f(x)=x(x+1) solve the inequality f(x) >6
Found 2 solutions by josgarithmetic, ikleyn:
Answer by josgarithmetic(39616) About Me  (Show Source):
Answer by ikleyn(52776) About Me  (Show Source):
You can put this solution on YOUR website!
.
x*(x+1) > 6   is equivalent to  

x%5E2+%2B+x > 6   is equivalent to

x%5E2+%2B+x+-+6 > 0   is equivalent to

(x+3)*(x-2) > 0.


The last inequality has two sets of solutions:  1)  x < -3,   and  2)  x > 2.

In the interval form: (-infinity,-3) U (2,infinity).

Solved.

Illustration:



Plot y = x*(x+1) (red line) and y = 6 (green line)


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The solution by @josgarithmetic is WRONG. For your safety, ignore it !