Algebra 1 (Reiny)

posted by .

Find the roots of each quadratic polynomial.

1. x^2 + 2
2. x^2 - 6x - 7

  • Algebra 1 (Reiny) -

    1. x^2 = -2
    x = +/- i sqrt 2 imaginary roots

    2. x = [ 6 +/- sqrt (36+28) ] / 2
    = 3 +/- 4
    7 or -1
    or just factor it
    (x-7)(x+1) = 0

  • Algebra 1 (Reiny) -

    I'm sorry, but I don't understand. I haven't learned about this solving method yet. What are imaginary roots?

  • Algebra 1 (Reiny) -

    If you have not learned about imaginary roots then you have a typo in number 1
    You can not solve
    x^2 = -2
    Unless you have had complex numbers.
    You can do number two the second way I did it, by factoring.

  • Algebra 1 (Reiny) -

    I haven't learned to factor quadratic equations yet, either. In my current lesson, I'm learning to solve quadratic equations by graphing. However, I am struggling to grasp the concept. Thus, what is a simple way to find the roots of quadratic equations by graphing?

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. algebra

    solve the polynomial y=2x^2-4x+1 For Further Reading algebra - Reiny, Thursday, May 17, 2007 at 10:34pm I am sure neither your text nor your teacher asked you to "solve the polynomial y=2x^2-4x+1 " are you graphing the function, or …
  2. Calculus

    Suppose that ax^2 + bx + c is a quadratic polynomial and that the integration: Int 1/(ax^2 + bx + c) dx produces a function with neither a logarithmic or inverse tangent term. What does this tell you about the roots of the polynomial?
  3. Algebra

    Given the roots, 1/2 and 4, find: (A) The quadratic equation 2x^2-9x+4 ?
  4. Alg II

    I'm working with finding roots of polynomial equations with degrees of 3 or higher. I have the equation r(x)=x^4-6x^3+12x^2=6x-13 I used a graphing calculator to find the real roots of 1,-1 Then I did synthetic using -1, and I ended …
  5. Alg II

    I'm working with finding roots of polynomial equations with degrees of 3 or higher. I have the equation r(x)=x^4-6x^3+12x^2=6x-13 I used a graphing calculator to find the real roots of 1,-1 Then I did synthetic using -1, and I ended …
  6. Algebra 2

    How do I solve polynomial equation by finding all complex roots?
  7. Algebra 1 (Reiny)

    Find the roots of each quadratic polynomial. 1. x^2 + 2 2. x^2 - 6x - 7
  8. Algebra 1

    Find the roots of each quadratic polynomial. 1. 16x + 40 + 2x^2 Solve. Round to the nearest hundredth. 2. 12 = 5x^2
  9. Math

    I can't remember how you find the roots of quadratic equations other than determining the zeroes of the equation and finding the x-intercepts. Can someone please give me a clear answer on this as my dad has been useless on this topic …
  10. Math

    Find the discriminant for the quadratic equation f(x) = 5x^2 - 2x + 7 and describe the nature of the roots. discriminant is 144, one real root discriminant is -136, two complex roots <--?

More Similar Questions