SOLUTION: Solve the quadratic inequality. Write the solution set in interval notation and show the complete solution. 2𝑥^2≤5𝑥−2

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: Solve the quadratic inequality. Write the solution set in interval notation and show the complete solution. 2𝑥^2≤5𝑥−2      Log On


   



Question 1087726: Solve the quadratic inequality. Write the solution set in interval notation and show the complete solution.
2𝑥^2≤5𝑥−2

Found 2 solutions by josgarithmetic, ikleyn:
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
2x%5E2-5x%2B2%3C=0
%282x-1%29%28x-2%29%3C=0
Critical x values are at 1%2F2%2Cand%2C2.
The quadratic expression will be BELOW 0 between 1%2F2 and 2.
For the "... equal to" part, the two values are included.
Interval Notation: [ 1/2, 2 ]

Answer by ikleyn(52779) About Me  (Show Source):
You can put this solution on YOUR website!
.
2x%5E2 <= 5x+-+2.

Move the terms from the right side to the left, changing the signs. You will get an equivalent inequality

2x%5E2+-+5x+%2B+2 <= 0.

Factor the left side:

(2x-1)*(x-2) <= 0.


Divide both sides by 2. You will get an equivalent inequality

(x-1/2)*(x-2) <= 0.     (1)


1)  If  x < 1%2F2  then both factors (each factor) in the left side of (1) are/is negative,
    So the product is positive.


2)  If  1%2F2 < x < 2  then the factor (x-1/2) is positive, while the factor (x-2) in the left side of (1) is negative,
    so the product is negative.


3)  If 2 < x  then both factors (each factor) in the left side of (1) are/is positive,
    so the product is positive.


Answer.  The given inequality has  the segment  [1/2,2] as the solution set.

Solved.


If you want to learn on how to solve quadratic inequalities, read the lesson
    - Solving problems on quadratic inequalities
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 lesson is the part of this online textbook under the topic "Inequalities".