Answer:
Using the quadratic formula:
x = [-4 +- sqr root (16 - 4 * 1 * -1)] / 2 *1
x = [-4 +- sqr root (20)] / 2
x1 = [-4 + sqr root (20)] / 2
x2 = [-4 - sqr root (20)] / 2
x1 = 0.23607
x2 = -4.2361
Step-by-step explanation:
Answer:
x = - 2 ± [tex]\sqrt{5}[/tex]
Step-by-step explanation:
Given
g(x) = x² + 4x - 1
To solve for x let g(x) = 0, that is
x² + 4x - 1 = 0 ( add 1 to both sides )
x² + 4x = 1
Using the method of completing the square
add ( half the coefficient of the x- term )² to both sides
x² + 2(2)x + 4 = 1 + 4
(x + 2)² = 5 ( take the square root of both sides )
x + 2 = ± [tex]\sqrt{5}[/tex] ( subtract 2 from both sides )
x = - 2 ± [tex]\sqrt{5}[/tex]
Thus solutions in exact form are
x = - 2 - [tex]\sqrt{5}[/tex] , x = - 2 + [tex]\sqrt{5}[/tex]
