rwbogl

 6 How can we sum up $\sin$ and $\cos$ series when the angles are in arithmetic progression? 4 Simplify [p∧ (¬(¬p v q)) ] v (p ∧ q) so that it become p, q, ¬p, or ¬q 4 Dummit and Foote problem 11 in section 7.4 3 Find the sum $\sqrt{5+\sqrt{11+\sqrt{19+\sqrt{29+\sqrt{41+\cdots}}}}}$ 3 Alternate Proofs that $\inf A = - \sup\left(-A\right)$ from Rudin

### Reputation (1,066)

 +20 How can we sum up $\sin$ and $\cos$ series when the angles are in arithmetic progression? +2 Convergence of $\sum_{k=0}^n 1+\left(k+\frac{1}{2}\right)\ln\left(\frac{k}{k+1}\right)$ +15 Does $e^x e^x$ really equal $e^{2x}$? +5 Generating function of even Fibonacci numbers

### Questions (23)

 5 How many triangular numbers have exactly $d$ divisors? 5 Why does Herstein add all these extra hypotheses for a “simple” modules proof? 4 Rings in which the “mistake” $(x + y) / d = x / d + y$ is justified 3 Does $e^x e^x$ really equal $e^{2x}$? 3 How many graphs are “obviously” nonplanar?

### Tags (64)

 8 sequences-and-series × 13 6 arithmetic-progressions 7 abstract-algebra × 6 6 trigonometry 7 proof-verification × 5 4 algebra-precalculus × 3 7 ring-theory × 3 4 real-analysis × 3 6 summation × 4 4 boolean-algebra

### Accounts (5)

 Mathematics 1,066 rep 717 Stack Overflow 447 rep 510 TeX - LaTeX 108 rep 5 Academia 101 rep 2 Programming Puzzles & Code Golf 101 rep 1