Question

Inverse function of y = 2x + ln(x)

Answer 1

And I don't know what the W lambert function is...

Answer 2

you have to switch x and y in the equation and then solve for y

Answer 3

y = 2x + ln(x)

Interchange x and y and re-solve for y.

x = 2y + ln(y)
==> e^x = e^[2y + ln(y)]
==> e^x = e^(2y)*e^[ln(y)]
==> e^x = y*e^(2y)
==> 2*e^x = 2y*e^(2y)
==> W(2*e^x) = 2y <== y = x*e^x <=> x = W(y)
==> W(2*e^x)/2 = y

Therefore, the inverse is:

f^-1(x) = W(2*e^x)/2

Answer 4

@CliffSedge

Answer 5

Gimme a sec. I lost my pencil.

Answer 6

That is an answer off yahoo answers... Is this so called w-function needed?

Answer 7

lol..

Answer 8

I'm not sure if it's needed, but it can be used.