Number 6 is {{{y=4x^3 - 7}}} solve for x
{{{4x^3=y+7}}}
{{{x^3=(y+7)/4}}}
{{{x=root(3,(y+7)/4)}}}
{{{f^(-1)=root(3,(x+7)
And Number 7 is Replace
f
(
x
)
f
(
x
)
with
y
y
.
y
=
3
x
x
+
2
y
=
3
x
x
+
2
Interchange the variables.
x
=
3
y
y
+
2
x
=
3
y
y
+
2
Solve for
y
y
.
f
−
1
(
x
)
=
−
2
x
x
−
3