The Pointer

### Questions (476)

 9 Why/How does the determinant of the Hessian matrix, combined with the 2nd derivatives, tell us max., min., saddle points? Reasoning behind it? 8 Determining Whether the Number $11111$ is Prime. Used Divisibility Tests. 8 Consistency of ZFC and proof by contradiction 7 Proof: For any integer $n$ with $n \ge 1$, the number of permutations of a set with $n$ elements is $n!$. 6 Help Solving Textbook Heat Conduction Laplace Transforms PDE Problem

### Reputation (2,512)

 +8 PDE Linearity Textbook Solution: $\mathscr{L} = \dfrac{\partial}{\partial{x}} + u\dfrac{\partial}{\partial{y}}$ +10 What's the difference between interior and relative interior? +5 What's the difference between continuous and piecewise continuous functions? +5 $\ln(x)$ Does Have a Laplace Transform?

 2 Finding Orthonormal Basis from Orthogonal Basis 1 Round off to decimals 1 What's the difference between interior and relative interior? 1 Analytically finding intersection points and bounds between a cylinder and two planes 1 Fourier series formula and the average value

### Tags (221)

 1 real-analysis × 86 1 volume × 4 1 integration × 49 1 convex-optimization × 3 1 geometry × 33 1 rounding-error 1 fourier-series × 21 1 decimal-expansion 1 cylindrical-coordinates × 4 1 rounding-unit

### Accounts (28)

 Mathematics 2,512 rep 31641 Stack Overflow 454 rep 2514 Cross Validated 332 rep 111 Electrical Engineering 332 rep 19 TeX - LaTeX 155 rep 7