1) Find the first and second derivatives:
y = Square Root((x^2) + 1)
2) If f(x) = Square Root(1 + (x^3)) , find the second derivative (2). So x = 2.
To get the second derivative you have to use either the product or quotient rule as well as the chain rule.
I suggest writing the first derivative as $\displaystyle \frac{x}{(x^2 + 1)^{1/2}}$ and using the quotient rule to differentiate. To get the derivative of the denominator the chain rule is required.
A bit of algebra will be required to get the answer in the required form.