Question

Which two values of x are roots of the polynomial below x^2-11x+17

Answer 1

Answer

9.14   and 1.86

Explanation

x²-11x+17

The first thing is to equate it to zero.

x²-11x+17 = 0

x²-11x = -17

x² - 11x + (11/2)² = -17 + (11/2)²

(x² - 11/2)² = -17 + 121/4

(x - 11/2)² = 13.25

x -11/2 = √13.25                            or      x - 11/2 = -√13.25

x = √13.25 + 11/2                                            x = -√13.25 + 11/2

   = 3.64 + 5.5                                                     = -3.64 + 5.5

   = 9.14                                                              = 1.86