A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • 5 years ago

can someone explain the quadratic formula to me please

  • This Question is Closed
  1. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Yes, the quadratic formula is what you end up with when you "complete the square". "Completing the square" is proof that the quad formula works. Anything specific you wanna know?

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

    \[5x ^{2} +3x+ 7= 0\]how would i do it with the equation

  3. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Just curious, do you know what "quadratic" means? at first I thought it had to do with "4" ... but it is just a fancy name for a squared function like x^2.

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

    yea im learning about it in math but hes confusing me

  5. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Lets start with the basics and then I will get to your equation ok? Tell me what the quad formula is so I know you have a grasp on it.

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

    how to find continuity of function of 2 vars??

  7. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Hi think, that doesnt ring a bell. sorry... Are the variables independant or does one depend on the other?

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

    \[-b \sqrt{b ^{2}- 4 (bc} \div 2 (a) \]

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

    its like, lim(x,y)->(1,2){x/sqrt[2x+y]}}

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

    that just confused me

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

    david, for your question, a quadratic equation is which has x power 2, and what you mentioned now is the 'discriminant'

  12. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @think: that doesnt look familiar to me. David; it looks like you know the formula; but might have troubles with formatting it with the website... But yes, you are basically right. lets define a, b, and c. a = the first term; b= the middle term, and c= the last term. Does that make sense?

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

    that is a way to find out the roots

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

    yeah after that im lost and i asked him to help me and he confused me even more

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

    @amistre, its like limit of (x,y)->(1,2) with the function as x/ sqrt(2x + y)

  16. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    lets re-write the top like this: -(middle) +-sqrt(middle^2 - (4)(first)(last)) How does that look to you?

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

    that actually makes sense

  18. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @think, I would assume that any values of (x,y) that make the bottom a zero have something to do with it. But I am just not sure.

  19. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @David: good then lets call the bottom part of the formula: 2(first) does that help?

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

    yeah

  21. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    So what was your original equation again and lets see if we can work it out now.

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

    i think twas 5x^2 + 3x + 7 =0

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

    right?

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

    yea

  25. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @thnk: what happens when you plug in (1,2) into the equation, does it get a number or an indeterminiate value?

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

    thinker wat grade r u in

  27. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    5x^2 + 3x + 7 first = (+5) ; middle = (+3); and last = (+7) top of quad form: -3 +- sqrt(3^2 -(4)(5)(7)) ------------------------ bottom part: 2(5) What do we get?

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

    10

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

    sry..it freezed again....i get the answer as 1/2

  30. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    10 is the bottom of it; but what is the top part of the quad form equal; remember it is just a big fraction looking monstorcity :)

  31. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    then as (x,y) approaches (1,2) that was the original right? then the equation approaches (1/2) if you plugged it in correctly :)

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

    -3 +- sqrt 9 -140

  33. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    good; does (-3 + sqrt(-131)) / 10 have any meaning to you? In other words can we have any real values for sqrt(-131)? Let me ask it this way.... what number when multiplied by itself will give you a "negative" answer?+

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

    yeah...so what 's the continuity?

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

    no it has no real solution i think

  36. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @think; rationalize the denominator and see if that helps :)

  37. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @David; very good, that is the correct answer, there are no "real" values of 'x'. Tell me, what does it mean to be a "real" value?

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

    when a number has a square root??

  39. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @ david, good enough answer :) Have you dealt with "imaginary" numbers yet?

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

    no

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

    @amistre, have u anytime seen "Thomas' Calculus" text?

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

    oh r u tlking about the imaginery 1 in front of x

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

    @david, no..imaginary numbers are those which do not exist..like sqrt of a negative number etc

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

    oh

  45. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @think; doesnt ring a bell :) @david; lol....good attempt at, but no. the "1" infront of an x is actually there, we just dont write it because it is

  46. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    1(x) = x the only imaginary number there is, is called "i" and we simply define it as : i = sqrt(-1) it is the only way in which we can solve the squareroots of negative numbers.

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

    ohh..was just a try..not an "algebra" person

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

    @amistre, have u anytime seen "Thomas' Calculus" text??

  49. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Thomas Calculus text doesnt sound familiar to me...

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

    ohh..:(..its a huge book..which i have to study from..

  51. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    I have a few good books in the college library (public libraries here are a joke) that I use. Some are more helpful than others at times.

  52. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    How did we do with your 1/sqrt(2x+y) question so far?

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

    this function is continous only when the denominator,i.e x,y\[\neq\]0

  54. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    And do we know if y is a function of x; or if x is a function of y; or if they are independant variables?

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

    there's nothing mentioned...its just that we ve to find the points of continuity/discontinuity

  56. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    So when (2x+y) = 0 there is a Vertical Asymptote right? When y = -2x and when x = -y/2

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

    vertical asymptote? what is that?

  58. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    there are a few types of discontinuities available to us: the "hole" is a line is called a jump disconiuity becasue the line will forever get close to it and never touch it. the "vertical" asymptote is a value for "x" that the graph will forever slide right up next to but never touch so instead of a jump across a hole, we get a neverending curve that approaches "x"

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

    sry..didn't get that:(

  60. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Holes occur when you can cross out like factors top to bottom. VAs occur when whats left after crossing out makes the bottom equal to "0"

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

    @amistres64 may u pls help me

  62. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    that was odd... :) kabelo, what is your question? and maybe I can help

  63. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @think: think of the graph for f(x) = x^2; and restrict the domain to x<4 and x>4. there is no value for f(x) at x=4; it just makes a hole.

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

    i know is bascially algebra

  65. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    kab: basic algebra is good :) what is your question?

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

    the veranda is covered with tiles(30cm times 30cm) in 5 black and4 white tiles,how many black tiles are used to cover the veranda floor if that pattern is continued.the area is 4,2m

  67. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Kab: Ill go over to that posting , this ones getting rather long ok?

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

    can i join?

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

    yip pls do ,yes u can.

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

    what was the question there? unable to find it:(

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

    the veranda is covered with tiles(30cm times 30cm) in 5 black and4 white tiles,how many black tiles are used to cover the veranda floor if that pattern is continued.the area is 4,2m

  72. 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

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.