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barreraA

  • one year ago

Calculate the discriminant to determine the number of real roots. y = x2 + 3x + 9 How many real roots does the equation have? (Points : 5) one real root two real roots no real roots no solution to the equation

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  1. barreraA
    • one year ago
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    i think its between A or B @Nnesha

  2. mathstudent55
    • one year ago
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    Do you know what the discriminant is?

  3. barreraA
    • one year ago
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    no @mathstudent55

  4. mathstudent55
    • one year ago
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    |dw:1434495669530:dw|

  5. mathstudent55
    • one year ago
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    The drawing above shows the quadratic formula. It is used to solve quadratic equations.

  6. barreraA
    • one year ago
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    ok

  7. mathstudent55
    • one year ago
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    |dw:1434495759652:dw|

  8. mathstudent55
    • one year ago
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    The discriminant is the part inside the square root symbol. It is the part inside the rectangle.

  9. barreraA
    • one year ago
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    ok im starting to understand @mathstudent55

  10. mathstudent55
    • one year ago
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    If you have an equation of the form \(ax^2 + bx + c = 0\), you can use the quadratic formula to solve it. Before you even solve it, you can just evaluate the discriminant to find out the nature of the solutions. If the discriminant is positive, there are two real solutions. If the discriminant equals zero, there are two equal real solutions. If the discriminant is negative, there are two complex (imaginary) solutions.

  11. mathstudent55
    • one year ago
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    Your problem is: y = x2 + 3x + 9 We set the right side equal to zero, and now we have a quadratic equation. \(x^2 + 3x + 9 = 0\)

  12. mathstudent55
    • one year ago
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    If you compare your equation to \(ax^2 + bx + c = 0\) you see that in your equation, a = 1, b = 3, and c = 9.

  13. mathstudent55
    • one year ago
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    |dw:1434496073864:dw|

  14. mathstudent55
    • one year ago
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    |dw:1434496111258:dw|

  15. mathstudent55
    • one year ago
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    Now we use those values of a, b, and c in the discriminant to see what type of quadratic equation you have.

  16. mathstudent55
    • one year ago
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    |dw:1434496200738:dw|

  17. mathstudent55
    • one year ago
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    We see that the discriminant is a negative number. Now you can look above to find out what a negative discriminant tells you about the solutions of the quadratic equation.

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