Question

Evaluate if possible ​.




I will mark as........ st

Answer 1

Step-by-step explanation:

1st Matrix is 2×2 and 2nd matrix is 2×1. since column of 1st matrix = rows of 2nd matrix, these two matrices can be multiplied. the product will be 2 × 1 matrix.

=> [ 6 × (-1) + 4 × 3 ]

[ 3 × (-1) + (-1) × 3]

=> [ -6 + 12 ]

[ -3 + (-3)]

=> 6

=> 2 × 1 matrix

-6

Answer 2

cosA=5/13

sinA=-√(1-cos^2A) (since theta is in 4th quadrant)

i.e. sinA=-√144/169

=-12/13

tanB=-15/8

sinB=+(15)/√{(-15)^2+(8)^2} (B is in Q2)

i.e. sinB=15/17

cosB=tanB/sinB

i.e. cosB=-15/8 * 17/15

cosB=17/8

now

sin(A+B)=sinAcosB+cosAsinB

sin(A+B)=(-12/13)(17/8)+(5/13)(15/17)

={1/13}(-51/2 + 75/17)

=(1/13)(-710/34)

=-710/442