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anonymous
 one year ago
when graphing a quadratic equation x^2+2x=5 what would be the points I would plot for it. I know the axis of symmetry is 1.
anonymous
 one year ago
when graphing a quadratic equation x^2+2x=5 what would be the points I would plot for it. I know the axis of symmetry is 1.

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jtvatsim
 one year ago
Best ResponseYou've already chosen the best response.0It's a good practice to plot at least 3 points for a quadratic equation. It is always really helpful to plot the point for the axis of symmetry (plug in x =1 into the equation to get the y value). The other two points are up to you to pick. I might pick x = 0 since that is easy, and maybe x = 2. But it is really a matter of personal taste. There isn't a right or wrong way to pick these two points. :)

jtvatsim
 one year ago
Best ResponseYou've already chosen the best response.0But, wait, do you have an equal sign in your question?

jtvatsim
 one year ago
Best ResponseYou've already chosen the best response.0I may have misread that. :)

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0yes but when I do this problem i am stumped i'm told all of my work was wrong look for number 5 that is the problem i am having

jtvatsim
 one year ago
Best ResponseYou've already chosen the best response.0Number 5 looks fine to me, do you mean number 6?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0sorry my mistake yes it is number six not number 5

jtvatsim
 one year ago
Best ResponseYou've already chosen the best response.0OK, first thing, it looks like you added 5 to both sides. You needed to subtract 5 from both sides.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0okay but where do I subtract the five on one of the sides

jtvatsim
 one year ago
Best ResponseYou've already chosen the best response.0So, you have x^2 + 2x = 5. We will set this equal to 0 (that is usually the best way to do it). So, x^2 + 2x = 5 5 5 x^2 + 2x  5 = 0 Does that make sense?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0yes it does then what would be the next step

jtvatsim
 one year ago
Best ResponseYou've already chosen the best response.0OK, probably we should find the axis of symmetry, which you did and found it was x = 1.

jtvatsim
 one year ago
Best ResponseYou've already chosen the best response.0That's correct. So let's find the yvalue that goes with that by plugging in x = 1.

jtvatsim
 one year ago
Best ResponseYou've already chosen the best response.0(1)^2 + 2(1)  5 = 1+25=4 So the vertex is (1,4). Good so far?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0yes. Now what is next?

jtvatsim
 one year ago
Best ResponseYou've already chosen the best response.0Well, we want to see if there are any solutions, that make this equation 0, but there probably won't because of the x^2. You can see the shape of the graph by plugging in two random points. I would suggest x = 0 and x = 2 since they are small and close to the axis of symmetry.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0I need to have two point of the right and left pf the vertex and the solution is 1

jtvatsim
 one year ago
Best ResponseYou've already chosen the best response.0OK, you've almost got it. Yes, it's a good idea to have two points of the right and left of the vertex. However, the "solution" is not 1. There are none for this graph. Let me explain using the picture.

jtvatsim
 one year ago
Best ResponseYou've already chosen the best response.0dw:1437167305706:dw

jtvatsim
 one year ago
Best ResponseYou've already chosen the best response.0That 4 should be by the vertex, but you get the point. :)

jtvatsim
 one year ago
Best ResponseYou've already chosen the best response.0So, what we have done is we have drawn the graph of x^2 +2x  5 by plotting the points.

jtvatsim
 one year ago
Best ResponseYou've already chosen the best response.0Now, in order to see if there are ANY solutions to x^2 + 2x  5 = 0, we want to see if the graph ever crosses the xaxis. Wherever the graph crosses the xaxis is a solution.

jtvatsim
 one year ago
Best ResponseYou've already chosen the best response.0But, from our picture we see that the graph never crosses the xaxis. So there are no solutions.

jtvatsim
 one year ago
Best ResponseYou've already chosen the best response.0It's a tricky idea, so do you have any questions about that?

jtvatsim
 one year ago
Best ResponseYou've already chosen the best response.0Step 1) Set equation = 0. Step 2) Draw the graph of the quadratic by finding axis of symmetry and choosing points. Step 3) See if the graph crosses the xaxis. Wherever it does this is a solution. If it doesn't there are no solutions.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0where would I plot the points that's what is confusing me the most.

jtvatsim
 one year ago
Best ResponseYou've already chosen the best response.0OK, that's a good question. For the axis of symmetry, we found x = 1, and y = 4. So we plot this.

jtvatsim
 one year ago
Best ResponseYou've already chosen the best response.0dw:1437167688817:dw

jtvatsim
 one year ago
Best ResponseYou've already chosen the best response.0That dot is the first point plotted for the axis of symmetry.

jtvatsim
 one year ago
Best ResponseYou've already chosen the best response.0Does that make sense so far? There's two more for us to plot. :)

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0I get that part easy it just the other points that i don't get

jtvatsim
 one year ago
Best ResponseYou've already chosen the best response.0OK, that's fine. It's actually really easy once you get the hang of it.

jtvatsim
 one year ago
Best ResponseYou've already chosen the best response.0So, I'm going to pick a random number. But I'll pick an easy one. How about x = 0? Then, I get 0^2 +2*0  5 = 0 + 0  5 = 5. So, I have x = 0, y = 5. as another point.

jtvatsim
 one year ago
Best ResponseYou've already chosen the best response.0dw:1437167834263:dw

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0that will be the same for x=2. correct?

jtvatsim
 one year ago
Best ResponseYou've already chosen the best response.0Yes, because of the axis of symmetry! So, x = 2, y = 5.

jtvatsim
 one year ago
Best ResponseYou've already chosen the best response.0dw:1437167900952:dw

jtvatsim
 one year ago
Best ResponseYou've already chosen the best response.0We can plot more points if we want, but I'm pretty convinced that this is what the graph looks like...

jtvatsim
 one year ago
Best ResponseYou've already chosen the best response.0dw:1437167946786:dw

jtvatsim
 one year ago
Best ResponseYou've already chosen the best response.0Of course, you'll want to be a better artist than me... :)

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0I agree with you my lines are a lot worse than you have seen.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Thank you so very much and sorry about my grammar with my sentence.

jtvatsim
 one year ago
Best ResponseYou've already chosen the best response.0Ah no worries, as long as I can help I don't mind. :) Nice work! You were very close to the right answer.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Thanks I have a hard time understanding math since I have autism which makes it harder for me to understand how to do certain things.
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