Any mathematicians out there?!

Pre-College Issues High School Life
1

<p>Well, I'm in the process of doing a review sheet for my advanced math topics midterm, and am stumped on two questions. I did try them already but have a feeling that I did something wrong, and I can't figure out what, despite reading through my notes.</p>

<p>Problem 1:
Solve by completing the square: 3x^2+9x+15=0</p>

<p>I ended up with x= -1.5i+or- radical 2.75 . I don't believe this is correct, and if anyone could solve this and walk me through the steps so I understand where I messed up, I would be forever grateful.</p>

<p>Problem 2:
Write the equation in vertex form and find the vertex: y=6x^2-12x+1</p>

<p>I got 6(x-1)^2+13 as the equation, and (1,13) as the vertex, but again I believe that I messed up somewhere.</p>

<p>Thank you in advance for any help!</p>

2

<ol>
<li><p>Complete the square is only possible when the coefficient of x^2 is 1.</p></li>
<li><p>This qualifies for homework help.</p></li>
<li><p>What’s the vertex? Remember how to find it.</p></li>
</ol>

3

<p>MIT is wrong, divide the entire first equation by 3 and complete the square</p>

4

<ol>
<li><p>I had just divided both sides by three, to elimiate the coefficent, so I started the equation with x^2+3x+5=0. I believe I messed up after there, though.</p></li>
<li><p>Is there a specific section for homework help? Ah- I apologize if there is. I didn’t know.</p></li>
<li><p>I know that the vertex formula is y=a(x-h)^2+k. I always thought that the vertex was (-h, k). Is that correct?</p></li>
</ol>

5

<p>

I believe MIT was trying to provide a hint without giving the whole thing away. Unlike you.</p>

<p>Homework help is forbidden on CC, but that rule is sometimes bent a little. Post at your own risk.</p>

<p>EDIT: Wolfram MathWorld is a good resource. Use it.</p>

6

<p>Oh, wow. I didn’t know. It isn’t homework, like something that counts for a grade- just a gradeless review sheet for a midterm, if that is different.</p>

7

<p>How am I wrong, I only said complete the square is possible when the coefficient of the x^2 term is one. Dividing by 3 makes the coefficient one dumbass.</p>

<p>I assumed that they knew to divide to be three.</p>

8

<p>[Here</a> you go](<a href=“solve 3x^2+ 9x + 15=0]Here - Wolfram|Alpha”>solve 3x^2+ 9x + 15=0 - Wolfram|Alpha)</p>

9

<p>this is advanced topics? use the quadratic equation.</p>

<p>also. HOMEWORK QUESTIONS ARE ABSOLUTELY NOT ALLOWED ON CC. </p>

<p>also.</p>

<p>use google</p>

<p>[How</a> to convert equation of parabola from vertex to standard form and from the standard equation to vertex form.](<a href=“File Not Found [404 Error]”>How to convert equation of parabola from vertex to standard form and from the standard equation to vertex form.)</p>

10

<p>

I’m not quite sure where the brightline on homework vs. self-study is placed. This sounds okay to me, but I’m not really the expert.</p>

11

<p>It is for an elective math course, that goes with the 10th grade algebra 2/trig course. I apologize for asking the question, but it isn’t homework and this won’t benefit any grade. I’m not cheating or anything because the sheet won’t be collected or graded or even looked at my the teacher. It’s just a resource to help me succeed, but if the thread needs to be taken down for some reason, mods can feel free to do so.</p>

<p>Thank you for the resources, though :)!</p>

12

<p>that elective sounds like a waste of time. i highly suggest you drop it.</p>

13

<p>How does it sound like a waste of time? It’s going deeper than the required course that I am taking goes. It probably sounds like basic stuff, but I’d rather learn it in an elective than not at all. It’s only every-other day as well, so it isn’t taking up a full every-day slot. Is it that pointless though? I’m not sure, so can you tell me why it would be?</p>

14

<p>Is this Algebra II?</p>

<p>HappyJones gave the answer for your first question.</p>

<p>For scoend one:
formula: y=ax^2+bx+c
x of vertex is -b/(2a)</p>

<p>Let me walk you through:
y = 6x^2-12x+1
= 6(x^2-2x+1/6)
= 6(x^2-2x+1-5/6)
= 6[(x-1)^2-5/6]
= 6(x-1)^2-5</p>

<p>So the vertex is (1,-5)</p>

15

<p>dude when you said advanced math, i thought you meant something like Diff Eq or Calc 3, not algebra 3-4</p>

16

<p>

HappyJones?</p>

17

<p>Okay, sorry, my bad :|</p>

<p>I just have low expectations for people’s math ability considering my school.</p>

18

<p>I don’t think one has to be a mathematician to know how to complete the square lol. But don’t drop something that takes you deeper into a subject. Especially because your school must suck if completing the square isn’t a"normal" part of Alg2. Your school sucking isn’t your fault though. So don’t worry about that.</p>

<p>Ps. This is coming from a senior at an extremely crappy public school.</p>