A) \[\frac{-5}{2}\]
B) \[6\]
C) \[-6\]
D) \[3\]
Correct Answer: A
Solution :
Projection of\[x\mathbf{i}-\mathbf{j}+\mathbf{k}\]on\[2\mathbf{i}-\mathbf{j}+5\mathbf{k}\] \[=\frac{(x\mathbf{i}-\mathbf{j}+\mathbf{k})\cdot (2\mathbf{i}-\mathbf{j}+5\mathbf{k})}{\sqrt{4+1+25}}=\frac{2x+1+5}{\sqrt{30}}\] But, given\[\frac{2x+6}{\sqrt{30}}=\frac{1}{\sqrt{30}}\] \[\Rightarrow \] \[2x+6=1\] \[\Rightarrow \] \[x=\frac{-5}{2}\]You need to login to perform this action.
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