Discussion #1

The code below solves the question c31 on pages 18-19 in “A First Course in Linear Algebra” by Robert A. Beezer

The system of equations are as follows:

3x + 2y = 1

x - y = 2

4x + 2y = 2

Solution is: [1,-1] for x, y

A <-  array(c(3,1,4,2,-1,2), dim=c(3,2))
b <-  c(1,2,2)

print(A)
##      [,1] [,2]
## [1,]    3    2
## [2,]    1   -1
## [3,]    4    2
print(b)
## [1] 1 2 2
# print(solve(A) %*% c(1,2,2))

print(qr.solve(A,b))
## [1]  1 -1