Partition matrices: Consider using a partition matrix in OLS. That is, consider X = [X1,X2] and = 1 2 where X1 is n × r1, X1 is n × r2, 1 is r1 × 1, 2 is r2 × 1, and r1 + r2 = r, the overall number of columns in X. When we take the inverse of a 2 × 2 partition matrix A B C D −1 = (A − BC−1D)−1 −(A − BD−1C)−1BD−1 −(D − CA−1B)−1CA−1 (D − CA−1B)−1 Find the equations for ˆ 1 and ˆ 2 using the OLS estimator ˆ = (X0X)−1X0y

all it means is function 3

b

step-by-step explanation:

the equation of a line in point- slope form is

y - b = m(x - a)

where m is the slope and (a, b) a point on the line

calculate m using the slope formula

m = (y₂ - y₁ ) / (x₂ - x₁ )

with (x₁, y₁ ) = (0, 4) and (x₂, y₂ ) = (3, - 5) ← 2 points on the line

m = = = - 3

with m = - 3 and (a, b) = (3, - 5), then

y - (- 5) = - 3(x - 3), that is

y + 5 = - 3(x - 3) → b

m∠5 + m∠3 = m∠1   is true.

m∠5 + m∠6 = 180 is true

m∠2 +m∠3 = m∠6   is true

m∠2 +m∠3 +m∠5 = 180   is true

show da graph

step-by-step explanation: