Question

1)
What is the range of f(x) = -x2 + 4, if the domain is {2,0,1}?
A)
{0,3,5}
B)
{0,4,3}
C)
{0,4,5}
D)
{8,4,3}

@hero @thesmartone @michele_lanio

Answer 1

the requested range is given by the subsequent subset of the real line:
\[\huge range = \left\{ {f\left( 0 \right),\quad f\left( 1 \right),\quad f\left( 2 \right)} \right\}\]

Answer 2

so, we have to compute these quantities:
\[\huge \begin{gathered}
f\left( 0 \right) = - {\left( 0 \right)^2} + 4 = ...? \hfill \\
\hfill \\
f\left( 1 \right) = - {\left( 1 \right)^2} + 4 = ...? \hfill \\
\hfill \\
f\left( 2 \right) = - {\left( 2 \right)^2} + 4 = ...? \hfill \\
\end{gathered} \]

Answer 3

sooo

Answer 4

im still confused

Answer 5

what is:
\(0 \cdot 0+4=...?\)

Answer 6

we have \(0 \cdot 0 +4=4\) so \(f(0)=-(0\cdot 0 )+4=4\)
then \(y=4\) belong to the requested range
now, please do the same with \(f(1)\)

Answer 7

belongs*

Answer 8

so 0,4,5

Answer 9

\(y=0,\;y=4\) are correct!
whereas we have: \(f(1)=-(1 \cdot 1)+4=-1+4=...?\)

Answer 10

0,3

Answer 11

it si \(f(1)=3\), so the requested range is the set
\(y=0\)
\(y=3\)
and
\(y=4\)
so, what is the right option?

Answer 12

b

Answer 13

that's right!

Answer 14

cant u help me on the next ones

Answer 15

ok!