# How can I prove $U(x) = [𝛼_1𝑥_1^𝜌+𝛼_2𝑥_2^𝜌]^{(1/𝜌)}$ is equal to Cobb-douglas Utility function when $𝜌\rightarrow0$ [closed]

This is the question, I have problem with part b, I don't know what function should I use to reach the result thanks in forward

Hint: find $$\ln(U(x))$$ and then use L'Hopital's rule to find the limit as $$\rho\rightarrow0$$.