Question

Suppose vector A=3i_2j+k ; vector B=-i-4j+3k and vector C is lyingbalong x-axis with the property that A.(B+C)=0,then calculate the vector C.

Answer 1

C = x i + 0 j + 0 k

I assume you mean A = 3 i - 2 j + 1 k
and B = -1 i - 4 j + 3 k

then B + C = (x-1) i +( 0-4) j + (0+3) k

Now if you mean A dot (B+C) =0
3(x-1) -2 ( -4) + (3) = 0
3 x -3 + 8 + 3 = 0
x = -8/3
so C = -8/3 i + 0j + 0 k
check my arithmetic