Question 1093352: please help me solve this equation in interval notation
x^3+5x<6x^2
I tried moving it to one side and did synthetic division which gave me x(x-5) and then I did the sign diagram of the 0 and 5 and got that it was smaller than 0 at (0,5) but it was incorrect
Answer by ikleyn(52794) (Show Source):
You can put this solution on YOUR website! .
x^3 + 5x < 6x^2 ====>
x^3 - 6x^2 + 5x < 0 ====> factor left side ====>
x*(x^2 -6x + 5) < 0 ====> factor the quadratic polynomial ====>
x*(x-5)*(x-1) < 0.
There are 3 critical points - the roots of the polynomial, where is becomes eqial to zero:
x = 0, x = 1 and x = 5,
and there are 4 intervals:
(-infinity,0), where the function is NEGATIVE;
(0,1), where the function is positive;
(1,5), where the function is negative; and
(5,infinity), where the function is positive.
Now YOU make an effort and complete the solution.
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See the lessons
- Solving problems on quadratic inequalities,
- Solving inequalities for high degree polynomials factored into a product of linear binomials
in this site.
Also, you have this free of charge online textbook in ALGEBRA-I in this site
- ALGEBRA-I - YOUR ONLINE TEXTBOOK.
The referred lessons are the part of this online textbook under the topic "Inequalities".
Save the link to this online textbook together with its description
Free of charge online textbook in ALGEBRA-I
https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson
to your archive and use it when it is needed.
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