Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

that1chick

  • 3 years ago

how do you write y = 2x2 + 6x + 4 in general form?

  • This Question is Closed
  1. iheartfood
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    do u know the general form?

  2. that1chick
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    yes, y=a(x-h)^2+k

  3. iheartfood
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    did u need it in linear form?

  4. iheartfood
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    like the general form of a linear equation?

  5. that1chick
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    just the general form of a quadratic equation

  6. iheartfood
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    okay, so u need to know the quadratic formula i believe..do u know it?

  7. that1chick
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    general form> y=a(x-h)^2+k

  8. that1chick
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    oh, yeah!

  9. that1chick
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    quadratic formula> -b+-sqrt(b-4(a)(c))/2(a)

  10. that1chick
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    but how does that help convert it to general form?

  11. that1chick
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    I thought it just helped find the x-intercepts..

  12. iheartfood
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    if i can remember this correctly, i believe u need to first solve to get the values of a,b,c and then you just plug it into the general form... I'm not 100% sure tho... @abb0t, am i remembering this correctly? ;/

  13. that1chick
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    I know how to convert it... the problem is the 2 in 2x^2

  14. abb0t
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    General form of what?

  15. that1chick
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    quadratic equations

  16. that1chick
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    2 in 2x^2 is the problem.... you isolate the x variables getting: y-4=2x^2+6x then complete the square and balance the equation: 6/2=3 3^2=9, y-4+9=2x^2+6x+9, y+5=2x^2+6x+9 then convert the trinomial into a binomial... thus lies my dilemma

  17. iheartfood
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    sorry, i'm not very sure, cuz i don't think i remember this correctly ahha and i don't wanna help u wrongly haha @Mertsj probs knows :) good luck!!! :D

  18. that1chick
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    thanks (:

  19. Mertsj
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    \[y=2x^2+6x+4\] \[y=2(x^2+3x+______ )+4\]

  20. Mertsj
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Now complete the square by adding (3/2)^2 inside the parentheses: \[y=2(x^2+3x+(\frac{3}{2})^2)+4-\frac{9}{2}\]

  21. Mertsj
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Now factor: \[y=2(x+\frac{3}{2})^2-\frac{1}{2}\]

  22. that1chick
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    why 3/2?

  23. Mertsj
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    I want to show you something: \[x^2+6x+9=(x+3)^2\]

  24. Mertsj
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    \[x^2+8x+16=(x+4)^2\]

  25. that1chick
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    I don't get what you did with: (3/2^2)+4−92

  26. Mertsj
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Notice the relationship between the coefficient of x and the constant term in a trinomial square.

  27. Mertsj
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    If you take 1/2 the coefficient and square it, you get the constant term.

  28. Mertsj
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    So I took 1/2 of 3 and got 3/2. Then I squared it and added it to the x^2 + 3x to get a trinomial square.

  29. Mertsj
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Now the (3/2)^2 was inside a parenthesis which has a 2 in front of it so I was really adding 2 times (3/2)^2 which is 2 times 9/4 which is 9/2. So since I could not change the equation, I then had to subtract 9/2.

  30. Mertsj
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Follow me?

  31. that1chick
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    I think so

  32. that1chick
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Okay, yes! I get what you did (: thank you! what were you trying to show me with those other two equations?

  33. Mertsj
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    The relationship between the coefficient of x and the constant term.

  34. that1chick
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    oh, that half of the coefficient of x to the second power = the constant. okay, cool

  35. that1chick
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Thank you for helping me (:

  36. Mertsj
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    yw

  37. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy