Question

Resolver a equação em R:
x² - 2(a+1)x + 4a = 0

Answer 1

Δ = B² - 4AC
Δ = [2(a+1)]² - 4.1.4a
Δ = 4(a²+2a+1) - 16a
Δ = 4a² + 8a + 4 - 16a
Δ = 4a² - 8a +4
Δ = 4 (a² - 2a + 1) -> 4 (a-1)²
√Δ = √4(a-1)² = 2(a-1) = 2a-2

Logo
x = 2a+2 +/- 2a-2/2
x1 = 2a
x2 = 2

S = {2a,2}