Question

Quais são as raízes da função f(x) = x2 + 6x – 16?

Answer 1

f(x) = x² - 6x - 16

iguala a função a zero e usa baskara

f(x) = 0

0 = x² - 6x - 16

Δ = (-6)² - 4.1.(-16)

Δ = 36 + 64

Δ = 100

x = - (-6) + - √100 /2.1

x' = 6 + 10 / 2

x' = 16 / 2

x' = 8

Answer 2

$x=\frac{-b\pm\sqrt{b^2} }{2a} =\frac{-6\pm\sqrt{6^2-4\cdot1\cdot(-16)} }{2\cdot1} =\frac{-6\pm\sqrt{36+64} }{2} =\frac{-6\pm\sqrt{100} }{2} =\frac{-6\pm10}{2} \\\\x'=\frac{-6+10}{2} =\frac{4}{2} =2\\\\x''=\frac{-6-10}{2} =\frac{-16}{2} =-8\\\\S=\{-8, \ 2 \}$