Question

determine o zeros da função f(x)=x²-2x-3=0​

Answer 1

f(x) = x² - 2x - 3

x² - 2x - 3 = 0

a = 1

b = - 2

c = - 3

∆ = b ² - 4 . a . c

∆ = (-2)² - 4 . 1 . (-3)

∆ = 4 + 12

∆ = 16

x = - b ± √∆

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2a

x' = -(-2) - 4

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2 . 1

x' = 2 - 4

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2

x' = - 2

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2

x' = - 1

x" = -(-2) + 4

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2 . 1

x" = 2 + 4

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2

x" = 6

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2

x" = 3

S = { - 1 ; 3}