K. Claesson's user avatar
K. Claesson's user avatar
K. Claesson's user avatar
K. Claesson
  • Member for 6 years, 5 months
  • Last seen more than 1 year ago
16 votes
3 answers
5k views

What is the cardinality of the union A∪B∪...∪Z?

5 votes
2 answers
120 views

What is $15^{15} + 16^{16} + 17^{17} + 18^{18} + 19^{19} + 20^{20} \pmod{7}$?

4 votes
3 answers
1k views

How can the correct form of the partial fractions decomposition be found for arbitrary rational functions?

2 votes
4 answers
65 views

If $f(x) \rightarrow c > 0$ when $x \rightarrow \infty$, is it true that its anti-derivative $F(x) \rightarrow \infty$ when $x \rightarrow \infty$?

2 votes
0 answers
3k views

What is the formula for the local truncation error in RK4?

2 votes
2 answers
457 views

The general equation of a conic section in the plane of the conic

2 votes
7 answers
2k views

Is there anyway to see that $h(x,y) = \frac{20}{3+x^2+2y^2}$ represents a graph looking like a mountain?

2 votes
1 answer
42 views

Evaluate $I = \iint_S x~dS$ over the part of $2z = x^2$ that lies in the first octant part of $x^2 + y^2 = 1$.

1 vote
0 answers
45 views

Optimizing a linear combination inequality with additional requirements on the vectors

1 vote
1 answer
170 views

Converting piecewise functions into single expressions

1 vote
1 answer
819 views

An equation for a pencil of planes

1 vote
2 answers
2k views

Defining differentiablity of a function of two variables

1 vote
1 answer
63 views

Does $\int_{0}^{\pi ^2} \frac{dx}{1 - \cos \sqrt{x}}$ converge or diverge?

1 vote
0 answers
58 views

Finding the angle at which a ball should be thrown to pass through a given coordinate

1 vote
4 answers
178 views

Is it possible to convert the parametric curve defined by $x = t^3 - 3t$ and $y = t^2 - 4$ to an implicit function?

1 vote
6 answers
1k views

Finding the determinant of {{1,2,3}, {4,5,6}, {7,8,9}} by inspection.

1 vote
1 answer
30 views

Is it possible to solve $n=\text{floor}\left(\frac{L-1}{k}\right)$ for $L$?

1 vote
4 answers
66 views

Is it possible to create a cubic function that coincides with a trigonometric function in the interval between two local extremums?

1 vote
0 answers
350 views

Floating-point rounding error in numerical differentiation formula

0 votes
0 answers
32 views

The average value of each of a raffle participant's tickets

0 votes
1 answer
114 views

Given that x is a constructible number, how does one prove that 1/x is constructible?

0 votes
2 answers
73 views

Is it possible to analytically solve k * ∑(1/n) = 150, n = 1 to 2k for k?

0 votes
1 answer
69 views

Does there exist a notation for the number of terms in a sum?

0 votes
1 answer
38 views

Given that at least $n$ elements from $A$ must be members in $C$, how many different sets C can be created by combining elements from $A$ and $B$?

0 votes
1 answer
701 views

Prove that $p|nm \Rightarrow p|n \lor p|m, \hspace{0,1 cm} p$ is a prime; $n,m \in \mathbb{Z}$

0 votes
1 answer
117 views

What is the number of ways in which a fence can be colored if it consists of 45 pickets and there are 5 colors?

0 votes
2 answers
68 views

Why can the equation of a line be written as $ (a_2 - b_1)(y - b_1) = (b_2 - b_1)(x - a_1)$?

0 votes
1 answer
1k views

Why is $W^\perp$ the null space of the basis of $W$?

0 votes
2 answers
2k views

Why does an orthogonal matrix have the property $Q^T Q = Q Q^T = I$? [duplicate]

0 votes
2 answers
308 views

How can the area of a paralellogram formed by two 3D vectors be computed without using the cross product?