Question
Consider = – 1, where ai. aj + bi. bj + ci.cj = and i, j = 1,2,3
Assertion(A) : The value of is equal to zero
Reason(R) : If A be square matrix of odd order such that AAT = I, then | A + I | = 0
- If both (A) and (R) are true, and (R) is the correct explanation of (A).
- If both (A) and (R) are true but (R) is not the correct explanation of (A).
- If (A) is true but (R) is false.
- If (A) is false but (R) is true.
The correct answer is: If (A) is true but (R) is false.
AAT = I
|A| |AT| = 1 |A|2 = 1 |A| = ± 1
|A + I| = |A + AAT| = |A|3 |I + AT|
= A3 | I + A |
when |A| = – 1 |A + I| = – |A + I|
2|A + I| = 0 |A + I| = 0
when |A| = 1 |A + I| = |A + I|
Reason is false
Let A =
A + I =
AAT == 1 |AAT| = 1 |A| = ± 1 but |A| = – 1
|A + I| = |A + AAT| = |A|3 |I + AT| = – |A + I|
|A + I| = 0
So assertion is true.
Related Questions to study
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Statement-I The equation has exactly one solution in [0, 2].
Statement-II For equations of type to have real solutions in should hold true.
In this question, we have to find the statements are the correct or not and statement 2 is correct explanation or not , is same like assertion and reason. Here, Start solving first Statement and try to prove it . Then solve the Statement-II . Remember cos a cosb -sin a sinb = cos ( a + b ) and sin a cosb + cosa sinb = sin( a+ b) .
Statement-I The equation has exactly one solution in [0, 2].
Statement-II For equations of type to have real solutions in should hold true.
In this question, we have to find the statements are the correct or not and statement 2 is correct explanation or not , is same like assertion and reason. Here, Start solving first Statement and try to prove it . Then solve the Statement-II . Remember cos a cosb -sin a sinb = cos ( a + b ) and sin a cosb + cosa sinb = sin( a+ b) .