Answer:
The error is at step (3) .
The correct step (3) will be,
![\log_{b}(\frac {b^{x}}{b^{y}})](https://tex.z-dn.net/?f=%5Clog_%7Bb%7D%28%5Cfrac%20%7Bb%5E%7Bx%7D%7D%7Bb%5E%7By%7D%7D%29)
=
[by using the laws of indices]
All other steps are correct.
Step-by-step explanation:
The error is at the step (3) , because the student has tried to prove the quotient rule of logarithms by using the property i.e., 'The quotient rule of logarithm' itself , i.e. ,by assuming the property does hold before proving it. So, the proof is fallacious.
The correct step (3) will be,
![\log_{b}(\frac {b^{x}}{b^{y}})](https://tex.z-dn.net/?f=%5Clog_%7Bb%7D%28%5Cfrac%20%7Bb%5E%7Bx%7D%7D%7Bb%5E%7By%7D%7D%29)
=
[by using the laws of indices]
All other steps are correct.