Ok guys, I need some more help with a question for my girlfriend. Basically she was given a problem on a test/quiz and the only way I know how to do it is with a method that she hasnt learned in class yet. So pretty much I want you guys to look it over and let me know if there is another method to the problem that she might know. The problem is…
$$2x^3 + 3x^2 \lt 11x + 6$$
She has to solve it and give the answer in interval notation. So I would first move everything from the right side to the left to have a third order polynomial. My next step would be to use the rational zero test to start finding a zero using synthetic division. After I found one zero, I would factor it out of the function, and i would be left with $(x-a)$*2nd orderpolynomial. I could factor out the polynomial and find my 3 zero's.
The only problem is, she didnt learn synthetic divison, rational zero test, or long division of polynomials. is there another way she could do this problem with knowledge she might have? i tried to briefly teach her my way and it went over her head
Best Answer
Factor like this $$2x^3 +3x^2 - 11x - 6 = (x-2)(2x+1)(x+3).$$ Then draw a sign chart.