Q3 of 127 Page 108

If then show that |2A| = 4|A|.

|A| =

We know that determinant of A is calculated as


= 1(2) - 2(4)


= 2 - 8


|A| = -6


LHS: |2A|




= 2(4) - 4(8)


= 8 - 32 = -24


|2A| = -24 …LHS


RHS: 4|A|


4|A|= 4(-6)


= -24


4|A| = -24 …RHS


LHS = RHS


Hence proved.


More from this chapter

All 127 →
2

2

5

If then show that |3A| = 27|A|

 5

Evaluate the determinants