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Find the values of lambda such that x ,y...

Find the values of `lambda` such that `x ,y ,z!=(0,0,0)a n d( hat i+ hat j+3 hat k)x+(3 hat i-3 hat j+ hat k)y+(-4 hat i+5 hat j)z=lambda(x hat i+y hat j+z hat k),w h e r e hat i , hat ja n d hat k` are unit vector along coordinate axes.

Text Solution

Verified by Experts

The correct Answer is:
`0, -1`

`(hati + hatj +3hatk)x + (3hati-3hatj +hatk)y+ (-4hati+5hatj)z`
`= lamda (x hati +yhatj+zhatk)`
Comparing coefficient of `hati, x + 3y -4z=lamda x`
`rArr (1-lamda)x + 3y- 4z =0" "` (i)
Comparing coefficient of `hatj, x-3y+5z= lamday`
`rAtr x - (3+lamda)y + 5z =0" " `(ii)
Comparing coefficient of `hatk, 3x+y+0z =lamda z`
`rArr 3x+y -lamda z =0" "` (iii)
All the above three equations are satisfied for x, y and z not all zero if
`|{:(1-lamda,,3,,-4),(1,,-(3+lamda),,5),(3,,1,,-lamda):}| =0`
or `" "(1-lamda)[3lamda +lamda^(2)-5]-3[-lamda -15]- 4[1+9+3 lamda] =0`
or `" " lamda^(3) + 2lamda^(2) +lamda =0`
or `" " lamda(lamda + 1)^(2) =0`
or `" " lamda =0, -1`
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Find the values of lambda such that x ,y ,z!=(0,0,0)a n d( hat i+ hat j+3 hat k)x+(3 hat i-3 hat j+ hat k)y+(-4 hat i+5 hat j)z=lambda(x hat i+y hat j+z hat k) , where hat i , hat j , hat k are unit vector along coordinate axes.

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Knowledge Check

  • The value of hat i ( hat j xx hat k) + hat j ( hat i xx hat k ) + hat k (hat i xx hat j) is

    A
    0
    B
    `-1`
    C
    1
    D
    3
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