Question

3.

x² + 2x = 1
A. List the values for a, b, and c from the quadratic above (hint: c is not 1!)
a=
b=
C =
B. Fill in the values of a, b, and c to the quadratic formula below
X=
-( ) ± √(
2(
)²-4(
)
)( )
C. Simplify each section (one number) of the quadratic formula from part B
(note that we have split the formula into two problems because of the ± symbol)
and x

Answer 1

a) a = 1 ; b = 2 ;c =-1

c) -1 + √2 ; -1 - √2

Explanation:

Solving a quadratic equation using quadratic formula:

x² + 2x = 1

a) x² + 2x - 1 = 0

Compare with ax² + bx + c = 0

a = 1 ; b = 2 and c = -1

b)

`\boxed{x=(-b \± √(b^2-4ac))/(2a)}`

`= (-2 \± √(2^2-4*1*(-1)))/(2*1)\\\\\\\\C) \ =(-2 \± √(4+4))/(2)\\\\=(-2 \± √(8))/(2)\\\\=(-2 \±2√(2))/(2)\\\\=(2(-1 \± √(2)))/(2)\\\\= -1 \± √(2)`

x = -1 + √2 or x = -1 -√2