Q10 of 25 Page 10

Show that the four points are coplanar.

Let the four points be A, B, C and D

and, if are coplanar then points are coplanar









= -4[(4×3)-(-1×3)]-(-6)[(-1×3)-(-8×3]+(-2)[(-1×-1)-(-8×4)]


-4[12+3]+6[-3+24]-2[1+32]


-60+126-66


-126+126



Hence, points are copalanar.


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