qual a resposta das equações?
Soluções para a tarefa
a) 3x² - 7x + 4 =
a = 3 b = - 7 c = 4
Δ = b² - 4ac x' = (- b - √Δ)/2a x" = (- b + √Δ)/2a
Δ = (-7)² - 4(3)(4) x' = {-(-7) - √1}/2(3) x" = {-(-7) + √1}/2(3)
Δ = 49 - 48 x' = (7 - 1)/6 x" = (7 + 1)/6
Δ = 1 x' = 6/6 x" = 8/6 (/2)
x' = 1 x" = 4/3
b) 9y² - 12y + 4 =
a = 9 b = - 12 c = 4
Δ = b² - 4ac x' = (- b - √Δ)/2a x" = (- b + √Δ)/2a
Δ = (-12)² - 4(9)(4) x' = {-(-12) - √0}/2(9) x" = {-(-12) + √0}/2(9)
Δ = 144 - 144 x' = (12 - 0)/18 x" = (12 + 0)/18
Δ = 0 x' = 12/18 (/6) x" = 12/18 (/6)
x' = 2/3 x" = 2/3
c) 4x² - 3x - 1 =
a = 4 b = - 3 c = - 1
Δ = b² - 4ac x' = (- b - √Δ)/2a x" = (- b + √Δ)/2a
Δ = (-3)² - 4(4)(-1) x' = {-(-3) - √25}/2(4) x" = {-(-3) + √25}/2(4)
Δ = 9 + 16 x' = (3 - 5)/8 x" = (3 + 5)/8
Δ = 25 x' = - 2/8 (/2) x" = 8/8
x' = - 1/4 x" = 1
d) 1y² - 6x - 7 =
a = 1 b = - 6 c = - 7
Δ = b² - 4ac x' = (- b - √Δ)/2a x" = (- b + √Δ)/2a
Δ = (-6)² - 4(1)(-7) x' = {-(-6) - √64}/2(1) x" = {-(-6) + √64}/2(1)
Δ = 36 + 28 x' = (6 - 8)/2 x" = (6 + 8)/2
Δ = 64 x' = - 2/2 x" = 14/2
x' = - 1 x" = 7