Let f(x)=ax2+1 for x>1x+a for x≤1 then f(x)is derivable at x=1 , if
a=0
a=12
a=1
a=2
f(x)=ax2+1 for x>1x+a for x≤1 f(x)=2ax for x>11 for x≤1 2a=1⇒a=12