यदि ` y = cos theta + sin theta ` तथा ` |{:(1+y,1-y,1-y),(1-y,1+y,1-y),(1-y,1-y,1+y):}|=0` ,तब
y का मान होगा

Options

A. 0 या 3
B. 0 या 4
C. 0 या 1
D. इनमे से कोई नहीं

Answer

A

Explanation

दिया है, ` |{:(1+y,1-y,1-y),(1-y,1+y,1-y),(1-y,1-y,1+y):}|=0`
` rArr |{:(3-y,1-y,1-y),(3-y,1+y,1-y),(3-y,1-y,1+y):}|=0`
`[ C_(1) to C_(1) + C_(2) + C_(3)]`
` rArr ( 3- y) |{:(1,1-y,1-y),(1,1+y,1-y),(1,1-y,1-y):}|=0`
` rArr ( 3-y ) |{:(0,2y,0),(0,0,2y):}|=0`
` [ R_(2) to R_(2) - R_(1) , R_(3) to R_(3) - R_(1)]`
` rArr ( 3- y) [ 4y^(2)] = 0 `
` rArr 4y^(2) (3-y) = 0 `
` rArr y = 0 "या " y = 3`