Question

12 Considere f uma função de Rem R dada por f(x) = 3x - x + 4. Calcule:
a) f(1)
b) f(-1)
c) f(0)
d)
$f( \frac{1}{2})$
​me ajudem pfvrrr

Answer 1

a)

$f(1)=3.1^{2} -1+4\\f(1)=3-1+4\\f(1)=2+4\\f(1)=6$

b)

$f(-1)=3.(-1)^{2} -(-1)+4\\f(-1)=-3+1+4\\f(-1)=-2+4\\f(-1)=2$

c)

$f(0)=3.0^{2} -0+4\\f(0)=0+0+4\\f(0)=4$

d)

$f(\frac{1}{2})= 3.(\frac{1}{2})^{2} -\frac{1}{2}+4\\f(\frac{1}{2})=3.\frac{1}{4}- \frac{1}{2}+4\\f(\frac{1}{2})=\frac{3}{4}- \frac{1}{2}+4\\\\f(\frac{1}{2})=\frac{3-2+16}{4} \\f(\frac{1}{2})=\frac{17}{4}$

e)

$f\sf(\sqrt{2} )=3.(\sqrt{2} )^{2} -\sqrt{2} +4\\ f\sf(\sqrt{2} )=3.2-\sqrt{2}+4\\f\sf(\sqrt{2} )=6-\sqrt{2}+4\\f\sf(\sqrt{2} )=6+4-\sqrt{2}\\f\sf(\sqrt{2} )=10-\sqrt{2}$