Question

Please help fast!

which two values of x are roots of the polynomial below?
x^2+3x+5

Answer 1

Question :

Which two values of x are roots of the polynomial below?

• x² + 3x + 5

Answer :

• The correct options are C and D.

To find root of a quadratic polynomial ax² + bx + c, we have a formula :

`\tt x = - \frac{ - b ± \sqrt{ {b}^(2) - 4ac } }{2a}`

Here, in the given polynomial,

• a = 1
• b = 3
• c = 5

`\tt : \implies x = - \frac{ - 3 ± \sqrt{ {3}^(2) - 4 * 1 * 5 } }{2 * 1} \\ \tt : \implies x = - ( - 3 ± √( 9 -20 ) )/(2) \\ \tt : \implies x = - ( - 3 ± √( 9 -20 ) )/(2) \\ \tt : \implies x = - ( - 3 ± √( - 11 ) )/(2) \\ \tt : \implies \color{cyan}x = - ( - 3 + √( - 11 ) )/(2) \: and \: x = - ( - 3 - √( - 11 ) )/(2)`

Hence, C and D are correct options.