Question

If y=sqrt(x^2+16), then d^2y/dx^2=?

Answer 1

okay, I will guess, that's how you denote, the second derivative of any function.
That only means "derivate the derivative"... Staright forward.
so, having the function and derivating it:
\[y=\sqrt{x^{2}+16}\]
\[\frac{ dy }{ dx }=\frac{ 1 }{ 2\sqrt{x^2+16} }(2x) \]
\[\frac{ dy }{ dx }=\frac{ 2x }{ 2\sqrt{x^2+16} }\]
\[\frac{ dy }{ dx }=\frac{ x }{ \sqrt{x^2+16} }\]
now, you'd have to derivate it again to find d^2y/dx^2

Answer 2

Okay, I got that part right. I think I just messed up something in the second derivative.

Answer 3

show me how you did it.