Question

Let f^-1(x)= 1/2x-5 Which points lie on the graph of y=f(x)? Show all your work

A (-4,-7),(6,-2)
B (-6,-2), (1,12)
C (-1,-12), (2, -6)
D (-8, 1), (2,6)

Answer 1

\[f^-1(x)= \frac{ 1 }{ 2 }x-5\]

Answer 2

the answer is B
\[f^-1(x)=\frac{ 1 }{ 2 }x-5\]
let f^-1(x)=y
\[y=\frac{ 1 }{ 2 }x-5\]
\[y+5=\frac{ 1 }{ 2 }x\]
2(y+5)=x
so,
f(x)=2(x+5)
f(x)=2x+5
Substituting x=-6,
f(-6)=2(-6)+10
f(-6)=-2
Substituting x=1
f(1)=2(1)+10
f(1)=12
So, the graph lies on the line (-6,-2) and (1,12)

Answer 3

Thank you!

Answer 4

your welcome :)