Solve the inequality 2x^2 -x + 3 >_ 0
The ^2 represents exponent of 2 and >_ means greater/less than or equal to. Possible answers are A: x <_ -2 or x >_ 3 B: -2 <_ x <_ 3 C: No solution. D: All Real Numbers.
factor \(\bf 2x^2 -x + 3\) what does it give you?
Do I split that into two parentheses groups?
yeap
(2x - 1) (x - 3)
So what now?
hmmm actually.... that'd give you \(\bf 2x^2-7x+3\) are you sure is \(\bf 2x^2-X+3\)?
well \(\bf 2x^2-x+3\)
So it should be reversed, some of the numbers?
for that doesn't factor out nicely
So should it be 3 and 1 reversed?
But that isn't part of the answer group.
hmmm right.. meaning is not \(\bf 2x^2-x+3\) so.... recheck your material.... you maybe missing a digit there
Let me see.
It was 2x^2 - x + 3 >_ 0
So I don't think I'm missing something here.
hmmm can you post a quick screenshot of the material?
\[Solve the Inequality: 2x ^{2} - x + 3 \ge 0 \]
With the same answers.
hmmm do you know how to take a screenshot? press the PrintScreen button on the keyboard, next to the F12 key then go to Paint and paste, save and post :)
for \(\bf 2x^2-x+3\) the factors are rational ones, or fractions, thus
So that would kind of eliminate at least one of them.
hmmm I see... you think is no solution or the ther....hmmm have you covered the quadratic equation?
Quadratic, could we walk through this one?
well.. if you haven't covered it, means, the exercise doesn't apply to it or you're not expected to use it to solve it...... so... was wondering how are you meant to solve it for "x" then?
I've covered it, it's just not my strong point.
factoring is one way, simple if the factors are integers in this case they're fractions though
But then again, it does mention quadratics.
hmm do you know what "quadratic" means?
It's a formula for solving equations.
well.... what chapter is this exercise meant to cover though? the idea is to, give an exercise related to the section in study, if you haven't used the quadratic formula, means, you're expected to solve it differently, maybe even graphically only
For right now, this one is meant to solve inequalities with quadratics.
hmmm ok..... so you're not really expected to get the actual value.. so let's take a peek at the graph http://fooplot.com/#W3sidHlwZSI6MCwiZXEiOiIyeF4yLXgrMyIsImNvbG9yIjoiI0NGMEYwRiJ9LHsidHlwZSI6MTAwMCwid2luZG93IjpbIi01LjQ0IiwiNy41NiIsIjAuNjYwMDAwMDAwMDAwMDAwMSIsIjguNjYiXX1d notice that graph, notice the x-axis notice the y-axis so you're being asked for what values on the x-axis, or "x" is the graph above 0 on the y-axis so... what do you think?
a parabola keeps on going endlessly btw, to the left and to the right
parabola, meaning the graph of the "quadratic" equation quadratic equation = equation of 2nd degree
It looks like it has a positive three in it.
well.. .is below the 3 btw you can use the mouse to drag the graph up or down on whatever direction to view more of it and you can use the middle mouse button to zoom in the "3" if you want is not 3, is less than 3
It's between two and three.
more like 2.88
But that still isn't one of the available options.
hmm lememm reread \(\bf 2x^2 -x + 3 >0\implies 2x^2 -x + 3 >{\color{blue}{ y}}\qquad \begin{cases} {\color{blue}{ y}}=0\\ x=? \end{cases}\) so.. what is "x" when "y = 0"
2 ?
anyhow, I'd make it short from the graph, the graph over the y-axis, goes as low as 2.88 or thereabouts, right below the 3 and from that point, it goes up, on the left or right side, it goes up, never down thus the graph "never touches the x-axis" because the lowest the y-value is, is about 2.88 when y= 0 is when the graph touches the x-axis |dw:1428362222392:dw|
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