given fx find f1x by using the xy interchange method fx 5x23
given f(x), find f-1(x) by using the x-y interchange method.
f(x)= 5(x-2)^3+9
Solution
f(x) = 5( x-2)^3 +9
Plug x = y and y =x
y =5( x-2)^3 +9
x= 5(y -2)^3 +9
(x -9) = 5(y -2)^3
y- 2 = [(x -9)/5]^1/3
y = 2 + [(x -9)/5]^1/3
f^-1(x) = 2 + [(x -9)/5]^1/3
