How do you solve for y in Ln (y-1) = 3 ln x +2?

1 Answer
Sep 16, 2016

With x > 0 and y >1, y=e^2x^3+1.
The graph is that part in Q1, above (0, 1), sans (0, 1)..

Explanation:

To keep logarithms as real numbers, x > 0 and y > 1.

Rearranging,

ln(y-1)-3ln x= ln(y-1)-ln(x^3)=ln((y-1)/x^3)=2

Inversely,

(y-1)/x^3=e^2. cross multiplying and rearranging,

y=e^2x^3+1

The graph is the part of this curve in #Q_1

and is above (0, 1), sans (0, 1).

Of course, the whole curve ( not the given part ) meets the x-axis y

= 0, at (-1/e^(2/3), 0).