Trebor

 13 How many points are needed to uniquely define an ellipse? 7 Convert infinite 2D plane integer coords to 1D number 5 Calculating the square root of 2 4 Is $\tan^{-1}(-1) = 3\pi /4$ or $=7\pi /4$? I understand they're both valid solutions, but what about places where the value is added/subtracted? 4 How to integrate $\int\frac{1}{\sqrt{x(x-9)(x-5)}}\,dx$?

### Reputation (1,198)

 +10 What is the maximum value of $\ln(x+\ln(x+\ln(x+\cdots)))-\ln x$? +45 Why cant I prove this trigonometric equation straight down? +15 How many points are needed to uniquely define an ellipse? +10 Is there a math expression equivalent to the conditional ternary operator?

### Questions (8)

 4 Prove that a surreal number is born in a finite stage if and only if it is of the form $\frac m{2^n}$. 3 Understanding a particular method of solving generalized version of Pell's equation 2 Why should we adopt the cumulative universe convention? 2 Do type constructors have type themselves? 1 Visually suggestive way to present a finite group

### Tags (93)

 13 linear-algebra × 2 8 algebraic-geometry × 2 12 conic-sections × 2 7 approximation × 2 10 calculus × 5 6 real-analysis × 5 8 integration × 5 6 recurrence-relations × 3 8 trigonometry × 4 6 prime-numbers × 2