$($a$)$ Differentiate

$($i$)y=6e^{2x}$

$($ii$)y=ln(x^2+1)$

$($b$)$ Evaluate the first$-$ and second$-$order derivatives of the cubic $y=x^3+2x^2-6x+7$ at $x=2,$ and hence state whether the graph is

$($i$)$ increasing or decreasing at this point.

$($ii$)$ convex or concave at this point.