For which value of aaa is the tangent to f(x)=eaxf(x) = e^{ax}f(x)=eax at x=0x=0x=0 also tangent to g(x)=x2+1g(x) = x^2 + 1g(x)=x2+1?
a=0a=0a=0
a=1a=1a=1
a=2a=2a=2
a=1/2a=1/2a=1/2