Select the appropriate values of x that are solutions to f(x)=0, where f(x)=2x^2+2x+8

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Shelly J. | Excellent Maths Tutoring for academic successExcellent Maths Tutoring for academic su...

Hi Valerie,

f(x)=0

f(x)=2x²+2x+8

2x²+2x+8=0

x²+x+4=0

By using the quadratic formula,

x = -1±√(1)²-4(1)(4)

2(1)

= -1±√-15

2

=-1/2±i√15/2

use the formula for solving a standard quadratic equation Ax2 + Bx + C = 0

x = (-B + √ (B2 - 4AC))/2A

In this question plug in A = 2, B =2 and C=8, if B2 - 4AC is negative or <0 the the solution of X would be comples number expressed in terms of i (√-1)

x= (-2 + √(4 - 4x2x8))/2x2

=> (-2 + √(-60))/4

x = -2/4 + √60i/4

:)

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