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Thomas 's user avatar
Thomas 's user avatar
Thomas
  • Member for 7 years, 5 months
  • Last seen more than 3 years ago
3 votes
2 answers
1k views

How to determine if a function is increasing.

3 votes
1 answer
1k views

Prove that the determinant of a matrix is zero

3 votes
0 answers
57 views

Verification of two proofs

3 votes
2 answers
144 views

How to find the limit of a function involving two variables.

3 votes
2 answers
2k views

If $f(x,y)=f(y,x)$ then $\frac{\partial f(x,y)}{\partial x}=\frac{\partial f(y,x)}{\partial y}$

2 votes
3 answers
162 views

Show that, if $f ' (x) = 1$ then $f(x) = x + C$

2 votes
3 answers
253 views

If f is a continuous function that's differentiable show that there exists $d∈(a,b)$ such that $f′(d)=0$

2 votes
3 answers
163 views

For what values of $s$ and $t$ is the matrix negative semidefinite?

2 votes
1 answer
5k views

Proof that a linear transformation is injective iff its null space is trivial

2 votes
3 answers
476 views

Show that $Span(x_1, x_2, x_3) ∩ Span(x_2, x_3, x_4) = Span(x_2, x_3)$.

2 votes
2 answers
673 views

For each $y ∈ R^n$ show that $L_y$ is a linear transformation and compute $\dim_R(\ker(L_y))$.

2 votes
1 answer
119 views

Show that $im(L_{I_n+A}) = E_1(A)$

2 votes
2 answers
2k views

The complex conjugate of a complex function.

1 vote
4 answers
299 views

Computing the determinant of a matrix

1 vote
1 answer
80 views

Determine the $\dim_F(Span(x_1,x_2,x_3,x_4,x_5))$ for $F=\mathbb{C},\mathbb{R},\mathbb{Q}$.

1 vote
1 answer
2k views

Show that the linear transformation is an isomorphism

1 vote
1 answer
1k views

Prove that a subset is an interval.

1 vote
2 answers
91 views

Proof of a limit as X tends towards 0

1 vote
3 answers
117 views

Proof involving the span of a set of vectors.

1 vote
1 answer
182 views

Proof that $\sqrt X$ doesn't tend to a limit as $X$ tends to infinity

1 vote
2 answers
4k views

How to prove something is a subspace

1 vote
1 answer
112 views

Confused about the null space of a matrix

1 vote
1 answer
420 views

If A is invertible prove that B is positive definite.

1 vote
3 answers
3k views

If $P$ is an orthogonal matrix its columns form an orthonormal set.

1 vote
2 answers
64 views

Showing that $\ln(x) < x − 1$ for all $x ∈ (0, 1)$

1 vote
1 answer
151 views

Determining the sign of a permutation

1 vote
2 answers
3k views

Proof that $a(x − y) = ax − ay$ for x and y in vector spaces.

0 votes
2 answers
1k views

Determine whether the vector $y$ is in the subspace of $R^ 4$ spanned by the columns of $A$.

0 votes
1 answer
1k views

Proof that something is a subspace given it's a subset of a vector space.

0 votes
0 answers
1k views

How to determine whether a set spans $P^2$