Question

Using the Completing the Square method, what are the zeros of the quadratic function f(x) = 2x2 + 8x - 3?

Answer 1

A.

Explanation:

1) to rewrite the given equation:

f(x)=2(x²+4x)-3; ⇔ f(x)=2(x²+4x+4)-3-8; ⇔ f(x)=2(x²+4x+4)-11; ⇔ f(x)=2(x+2)²-11;

2) the roots are:

`\left[\begin{array}{ccc}x=-\sqrt{(11)/(2)}-2 \\x=\sqrt{(11)/(2)}-2 \end{array}`

3) finally, the correct answer is A.