Question

dada a função definida por: f(x)=2x²-1 calcular:

a) f(3)
b) f(-7)
c) f(-1)
d) f( -1/2 )​

Answer 1

A)

$f(3) = 2 \times (3)^{2} - 1 \\ f(3) = 2 \times 9 - 1 \\ f(3) = 18 - 1 \\ f(3) = 17$

B)

$f( - 7) = 2 \times ( { - 7)}^{2} - 1 \\ f( - 7) = 2 \times 49 - 1 \\ f( - 7) = 98 - 1 \\ f( - 7) = 97$

C)

$f( - 1) = 2 \times ( { - 1)}^{2} - 1 \\ f( - 1) = 2 \times 1 - 1 \\ f( - 1) = 2 - 1 \\ f( - 1) = 1$

D )

$f( - \frac{1}{2} ) = 2 \times ( - \frac{1}{2})^{2} - 1 \\ f( - \frac{1}{2} ) = 2 \times \frac{1}{4} - 1 \\ f( - \frac{1}{2} ) = \frac{1}{2} - 1 \\ f( - \frac{1}{2} ) = - \frac{1}{2}$

Bons Estudos! ✌✌✌