Question

What are the approximate zeros of f(x) = -x^2 - 3x + 6?

Answer 1

Given:

f(x) = -x^2 - 3x + 6?

Required:

f(x) = -x^2 - 3x + 6?

Explanation:

$\begin{gathered} f(x)=-x^2-3x+6=0 \\ make\text{ the leading coefficient positive} \\ x^2+3x-6=0 \\ identifying\text{ the coefficients} \end{gathered}$

a=1,b=3,c=-6

$substitute\text{ into x=}\frac{-b\pm\sqrt{b^2-4ac}}{2a}$

we get

$\begin{gathered} x=\frac{-3\pm\sqrt{3^2-4\times(-6)}}{2} \\ \\ x=\frac{-3+\sqrt{33}}{2}\text{ or x =}\frac{-3+\sqrt{33}}{2} \end{gathered}$

Required answer:

$x=\frac{\pm3+\sqrt{33}}{2}$