limit of function

Question

limit of 4, (x^2-x-12)/(x^2-16)

Answer 1

applying L'Hôpital's rule, differentiating f(x)=x^2-x-12, f'(x)=2x-1; and g(x)=x^2-16, g'(x)=2x, so f'(4)/g'(4)=7/8. The limit as x approaches 4 is therefore 7/8 under the rule.