JAMB 1984 · UME · Q23

The quadratic equation whose roots are 1−131 - \sqrt{13} and 1+131 + \sqrt{13} is

Worked solution (try it first)
  1. The sum of the roots is (1−13)+(1+13)=2(1 - \sqrt{13}) + (1 + \sqrt{13}) = 2.
  2. The product is a difference of two squares: (1−13)(1+13)=1−13(1 - \sqrt{13})(1 + \sqrt{13}) = 1 - 13
    =−12= -12.
  3. The equation is x2−(sum)x+(product)=0x^2 - (\text{sum})x + (\text{product}) = 0, which is x2−2x−12=0x^2 - 2x - 12 = 0, option E.

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