The function f(x)=ln x is transformed into the equation f(x) = 4 ln x. Select the transformation that occurred.
Vertical stretch by a factor of 4
Translating right or left we would have to have y = ln ( x ± b)
Translating up or down we would have to have y = ln (x) ± c
A vertical stretch (or vertical compression ) has the form y = a * ln (x)
Here, "a" = 4