Q2 of 64 Page 43

Find the zeros of the following quadratic polynomials:

p(x) = x2 — 81

Here p(x) = x2 — 81


To find the zeros of p(x), let p(x) = 0


∴ x2 – 81 = 0


∴ (x)2 – (9)2 = 0


∴ (x – 9) (x + 9) = 0


[Using the identity: (a2 – b2) = (a – b) (a + b)]


∴ x = 9 or x = –9


–9 and 9 are the zeros of the quadratic polynomial p(x).


More from this chapter

All 64 →
2

Find the zeros of the following quadratic polynomials:

p(x) = 4x2 + 9x + 5

 2

Find the zeros of the following quadratic polynomials:

p(x) = 3x2 + 5x — 8

 2

Find the zeros of the following quadratic polynomials:

p(x) = x2 — x — 6

 3

Find the zeros, the sum of the zeros and the product of the zeros of the quadratic polynomial p(x) = 3x2 — x — 4