Where am I going wrong on this second derivative?
131769
How to derive this second derivative using the quotient rule?
47681
How to go about solving this question on differentials?
117338
Counterexample to second derivative test when f''(x) is not continuously differentiable
60897
Non-integer order derivative
59125
Why does this matrix give the derivative of a function?
12726
Differentiating both sides of a non-differential equation
151297
Second order partial of $f(x,y)=\frac{xy(x^2-y^2)}{x^2+y^2}$
146318
Derivative of f(x)=arth(lnx)
152895
What is wrong with this derivation of $\frac{d}{dx}x^2$?
134122
When is differentiating an equation valid?
74409
Differentiaion Calculus: Trig Inverse Function.
40549
How to proof the the derivative of $x^2$ is $2x$?
66181
Find the derivative of the function
100007
Express partial derivatives of second order (and the Laplacian) in polar coordinates
95598
Derivative of unit step function?
134871
Using definition of derivative to differentiate $f(x)= \sqrt{x}+1$
36990
Notation of the second derivative - Where does the d go?