Question

Dada a Função f, tal que f(x) = -x²+5x+6 calcule quando possível:
f(√ 2)
f (49/4 )

Answer 1

f(x) = -x² + 5x + 6

f(√2) = -(√2)² + 5.(√2) + 6
f(√2) = -(2) + 5√2 + 6
f(√2) = -2 + 5√2 + 6
f(√2) = 4 + 5√2


f(49/4) = -(49/4)² + 5.(49/4) + 6
f(49/4) = -(2401/16) + 245/4 + 6
f(49/4) = -2401/16 + 245/4 + 6

f(49/4) = $\frac{-2401 \ + \ 980 \ + \ 96}{16}$

$\boxed{\bold{f(49/4) = \frac{-1325}{16}}}$

ou

f(49/4) = -82,8125

Answer 2

Ítalo, sendo f(x) = -x² + 5x + 6  uma função real, é possível calcular.
Vamos ver:

f(√2) = -[(√2)²] + 5* (√2) + 6 = -[√2 * √2] + 5*√2 + 6 = -2 + 5√2 + 6 = 4 + 5√2


f(49/4) = -[(49/4)²] + 5(49/4) + 6 = -[49/4 * 49/4] + 245/4 + 6 = 

f(49/4) = -[2401/16] + [4* 245]/16 + [6 * 16] /16 = -1325/16

f(49/4) = -2401/16 + 980/16 + 96 /16 = -1325/16


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05/12/2015
Sepauto - SSRC
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