Let f:ℝ→(0,∞) and g:ℝ→ℝ be twice differentiable functions such that f11 and g11are continuous functions on ℝ  . Suppose f1(2)=g(2)=0,f11(2)≠0 and g'(2)≠0. If limx→2f(x)g(x)f'(x)g'(x)=1, then