Question

Find the zeros of the quadratic polynomial $9x^2-5$.

• A. $\frac{5}{9},-\frac{5}{9}$
• B. $\frac{5}{3},-\frac{5}{3}$
• C. $\frac{\sqrt{5}}{3},-\frac{\sqrt{5}}{3}$
• D. $\frac{\sqrt{3}}{5},-\frac{\sqrt{3}}{5}$

Answer 1

Answer: (C)

$\frac{\sqrt{5}}{3},-\frac{\sqrt{5}}{3}$

Zeros of $9x^2-5$ can be obtained by solving the equation $9x^2-5=0$
$\Rightarrow 9x^2=5$
$\Rightarrow x^2=\frac{5}{9}$
$\Rightarrow x=\pm \frac{\sqrt{5}}{3}$
Therefore, the zeros of $9x^2-5$ are $\pm \frac{\sqrt{5}}{3}$.