Multiple choice

(A) Which of the following quadratic polynomials has zeros -9 and 9

  1. $x-81=0$
  2. ${x^2} - 9=0$
  3. ${x^2} - 64=0$
  4. ${x^2} - 81=0$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A quadratic polynomial with zeros a and b is (x - a)(x - b). For zeros 9 and -9, (x - 9)(x + 9) = x^2 - 81.

AI explanation

A quadratic polynomial having zeroes alpha and beta is given by the expression x squared minus (alpha plus beta)x plus (alpha times beta). For the zeroes negative 9 and 9, the sum is 0 and the product is negative 81. Substituting these values gives the polynomial x squared minus 81 equals 0.

Keep practicing — related questions