119 Why is the absolute value function not differentiable at $x=0$? 29 Vertical bar sign in Discrete mathematics 22 Symbol for unknown relation? 12 Absolute value problem $|x-y|=|y-x|$ 12 Best way to solve $X^3-X^2-X-1=0$

### Reputation (7,441)

 +50 Why is the absolute value function not differentiable at $x=0$? +10 Tricky limits problem +10 Is a function defined at a single point continuous? +10 Vertical bar sign in Discrete mathematics

### Questions (42)

 13 Is a function defined at a single point continuous? 12 Sum of $n$ integers from set of size $2n-1$ divides $n$ 10 Prove that point is on the perimeter of circle 7 Finding double root of $x^5-x+\alpha$ 6 Disk with root in center with no other roots in polynomial

### Tags (139)

 160 calculus × 38 28 limits × 15 131 absolute-value × 2 22 relations 71 notation × 8 21 geometry × 10 44 algebra-precalculus × 19 21 functions × 8 33 discrete-mathematics × 4 20 real-analysis × 9

### Bookmarks (21)

 43 What is $\cdots ((((1/2)/(3/4))/((5/6)/(7/8)))/(((9/10)/(11/12))/((13/14)/(15/16))))/\cdots$? [duplicate] 39 Evaluating the limit of $\sqrt{2+\sqrt{2+\sqrt{2+\cdots+\sqrt[n]{2}}}}$ when $n\to\infty$ 30 Very tight prime bounds 28 "Honest" introductory real analysis book 25 Limit of $\lim_{x\rightarrow 1}\sqrt{x-\sqrt{x-\sqrt{x-\sqrt{x-.....}}}}$