Show that the cross-product term $\hat y'r$ from $ y'y$ is 0
127382
What is the expected correlation between residual and the dependent variable?
112179
Why don't the results of testing $H_0 : \beta = 0$ and $H_0 : {\rm cor}(X,Y)=0$ agree?
46265
Minimal polynomial of the operator $T:V\oplus W\to V\oplus W$
106609
Show that $e^{iy} = 1 + iy + \frac{\mu_1 y^2}{2}$ for all $y \in \mathbb{R}$ with $|\mu_1| \leq 1$
378
Does $\hat{\beta}=(X′X)^{−1}X′ \ Y$ simplify further?
54628
Properties of non-zero symmetric bilinear form
133884
A proof using Yoneda lemma
158343
how to prove an element is non-zero in a tensor-product
67106
Projection on the hyperplane $H: \sum x_i=0$
123724
Solve $(y')^2 - xy' + y = 0$
29653
Show that $xy=0$ is a variety but not a manifold
69715
Proving $\text{Var}{(\hat{y}_h)} = \sigma^2 \left(\frac{1}{n} + \frac{(x_h-\bar{x})^2}{S_{xx}}\right)$
63410
Proof on showing if F(x,y,z)=0 then product of partial derivatives (evaluated at an assigned coordinate) is -1
81181
Prove that $\det(M-I)=0$ if $\det(M)=1$ and $MM^T=I$
125161
Why is the Cartesian product of $A$ and $\varnothing$ empty?
1162
Why $\{\mathbf{0}\}$ has dimension zero?
59644
Proof of Cartesian product intersection