please explain the following:

Asked by  | 2nd Jun, 2009, 10:30: PM

Expert Answer:

let

d= xi+yj+zk

c.d=15(given)

so

2x-y+4z=15...(i)

now the vector d is parallel to a cross b (since is't perpendicular to both a and b)

so

d is parallel to 32i-j-14k

so the coefficients of i, j, and k for both these vectors must be proportional

x/32=y/-1=z/-14

let each equal to k(say)

so,

x=32k

y=-k

z=-14k

substitute these values of x, y and z in  (i)

you wil get  k=5/3

so

x=160/3

y=-5/3

z =-70/3

recheck

 substitute this in c.d and you will get the answer 15

Answered by  | 7th Jun, 2009, 04:50: PM

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