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Find coefficients a and b of quadratic equation x^2 ax b=0 if known that a and b are the roots of given equation.

User Skue
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Final answer:

The coefficients a and b of the quadratic equation x^2 + ax + b = 0, with a and b as roots, are -1 and 1, respectively, based on the sum and product of roots for a quadratic equation.

Step-by-step explanation:

To find the coefficients a and b of the quadratic equation x² + ax + b = 0, given that a and b are also the roots of the equation, we can use the fact that for a quadratic equation of the form ax² + bx + c = 0, the sum of the roots (-b/a) equals the coefficient of x (which is 'a' in our case), and the product of the roots (c/a) equals the constant term 'b'.

Therefore, applying these relationships, we have:

Sum of roots (a + b) = -a

Product of roots (a * b) = b

Which leads to the system of equations:

a + b = -a

a * b = b

To solve for a, from the first equation a + a = -b, which simplifies to 2a = -b. To solve for b, we can see from the second equation that if ab = b and b is not zero, a must equal 1 (because if b = 0, then the original equation x² = 0 would not be quadratic). Hence, the coefficient a = -1, and coefficient b = 1, since anything multiplied by 1 remains unchanged.

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