Question

One solution to a quadratic function, g, is given.

9 - √2i
Which statement is true?

A. Function g has no other solutions.
B. The other solution to function g is -9 + √2i
.
C. The other solution to function g is -9 - √2i
.
D. The other solution to function g is 9 + √2i
.

Answer 1

D. The other solution to function g is 9 + √2i

Explanation:

The roots of a quadratic equation of the form ax² + bx + c = 0

are

`x = -(b)/(2a) + (√(b^2-4ac))/(2a)\\and\\x = -(b)/(2a) - (√(b^2-4ac))/(2a)\\`

If one of the roots is 9 - √2i then

`-(b)/(2a) = 9`

and

`(√(b^2-4ac))/(2a) = 2i`

So if one root is 9 - √2i then the other root must be 9 -+ 2i

This is answer choice D