Question

What is the positive solution to the equation 0 = –x2 + 2x + 1? Quadratic formula: x = StartFraction negative b plus or minus StartRoot b squared minus 4 a c EndRoot Over 2 a EndFraction

Answer 1

x = 2 + √2 or x = 2 - √2

Explanation:

Edge 2021

Answer 2

x = 2 + √2

x = 2 - √2

Explanation:

- x² + 2x + 1 = 0

x² - 2x - 1 = 0

Here,

a = 1

b = - 2

c = - 1

Now,

Discriminant

D = b² - 4ac

= (-2)² - 4(1)(-1)

= 4 + 4

= 8

=2√2 > 0

Real and Distinct roots

x = - b +- √b² - 4ac/2a

= - (-2) +- √ = (-2)² - 4(1)(-1)/2(1)

= 2 +- √4 + 4/2

= 2 +- √8/2

= 2 +- 2√2/2

= 2 +- √2

x = 2 + √2 or x = 2 - √2