True/ False: If $f '(c) < 0$, then $f$ is concave down at $x = c$?
74673
True or false: if $f'(c)<0$, then $f$ is concave down at $x=c$?
147420
Equivalent definitions of convexity for $f\in\mathcal C^1(\mathbb R^n)$
56958
bounding a $C^1$ function that upholds $f'(t)\leq 1-f(t)^2$
135867
$f(x)=x^3$ is convex nor concave without to derivate
154247
Proving $f(x)$ attains $\max$ or $\min$ when $f(x)\to0$ as $|x|\to\infty$.
16375
Is the function differentiable at $0$?
72033
Is this proof sufficient to show that a concave function of a metric is also a metric?
126259
Minimum of a function on an open interval
144439
For a $C^1$ function, the difference $|{g'(c)} - {{g(d)-g(c)} \over {d-c}} |$ is small when $|d-c|$ is small
22294
Maximum and minimum value of $\int_0^1 f(x)dx $ given $|f'(x)|<2$
76790
Condition to guarantee $f=0$ on $[a,b]$
2717
Help proving existence of an specific $x_0$ for which $f''(x_0)=0$
7825
If $f$ is a concave function and $f(0) \geq 0$ then $f(a+b) \leq f(a) + f(b)$ for all $a,b >0$
16463
Is the function $\mbox{tr}(XAX')$ convex?
85153
Show that $f(x) = -\ln(x)$ is convex (WITHOUT using second derivative!)
87743
Is a function whose derivative vanishes at rationals constant?
74810
A function $f$ such that $f' = 0$ when $x < 0$ and $f' = 1$ when $x \geq 0$?