1) If f:R→R is twice differentablr function such that f''(x)>0, for all xε R, and f(12)=12 , f(1)=1, then A) f″(1)≤0 B) f′(1)>1 C) 0<f′(1)≤12 D) 12<f′(1)≤1 Answer: Option BExplanation:f'(x) is increasing For some x in (12,1) f'(x)=1 f'(1)>1