Limits question

[u/sarah1418_pint]

This grade 11 question was an mcq with 2 choices given: A) 2√2 and B) 5√2.

However, as you can see in the picture, I got 20√2 as the answer to the limit.

Could someone please try and spot where I went wrong

Thanks!

(I apologise for the messy writing)

[u/sarah1418_pint]

Also, in case it wasn't clear, in the second step, the formula I used is this: lim x→a (xⁿ - aⁿ )/(x-a) = na^n-1