Post 1 - Exercise C10 in Chapter M

Elina Azrilyan

I am going to solve Exercise C10 in Chapter M.

A = matrix(c(1, 4, -3, 6, 3, 0), nrow=2, ncol=3, byrow = TRUE) 
B = matrix(c(3, 2, 1, -2, -6, 5), nrow=2, ncol=3, byrow = TRUE) 
C = matrix(c(2, 4, 4, 0, -2, 2), nrow=3, ncol=2, byrow = TRUE) 

alpha = 4
beta = 0.5

Calculation 1: A + B

A+B

##      [,1] [,2] [,3]
## [1,]    4    6   -2
## [2,]    4   -3    5

Calculation 2: A + C

A+C cannot be calculated - they are non-conformable arrays.

Calculation 3: Bt + C

t(B)+C

##      [,1] [,2]
## [1,]    5    2
## [2,]    6   -6
## [3,]   -1    7

Calculation 4: A + Bt

A+Bt cannot be calculated - they are non-conformable arrays.

Calculation 5: beta * C

beta*C

##      [,1] [,2]
## [1,]    1    2
## [2,]    2    0
## [3,]   -1    1

Calculation 6: 4A - 3B

4*A - 3*B

##      [,1] [,2] [,3]
## [1,]   -5   10  -15
## [2,]   30   30  -15

Calculation 7: At + alpha*C

t(A)+alpha*C

##      [,1] [,2]
## [1,]    9   22
## [2,]   20    3
## [3,]  -11    8

Calculation 8: A + B - Ct

A+B-t(C)

##      [,1] [,2] [,3]
## [1,]    2    2    0
## [2,]    0   -3    3

Calculation 8: 4A + 2B - 5Ct

4*A+2*B-5*t(C)

##      [,1] [,2] [,3]
## [1,]    0    0    0
## [2,]    0    0    0