A line is drawn in the direction and it passes through a point with position vector Find the equations of the line in the vector as well as Cartesian forms.
A line is drawn in the direction and it passes through a point with position vector Find the equations of the line in the vector as well as Cartesian forms.

A line is drawn in the direction of (\hat{\mathrm{i}}+\hat{\mathrm{j}}-2 \hat{\mathrm{k}}) and it passes through a point with position vector (2 \hat{i}-\hat{j}-4 \hat{k}) . Find the equations of the line in the vector as well as Cartesian forms.
Answer
Given: line passes through 2 \hat{\imath}-\hat{\jmath}-4 \hat{k} and is drawn in the direction of \hat{i}+\hat{\jmath}-2 \hat{k}
To find: equation of line in vector and Cartesian forms
Formula Used: Equation of a line is
Vector form: \overrightarrow{\mathrm{I}}=\overrightarrow{\mathrm{a}}+\lambda \overrightarrow{\mathrm{b}}
Cartesian form: \frac{\mathrm{x}-\mathrm{x}_{1}}{\mathrm{~b}_{\mathrm{n}}}=\frac{\mathrm{y}-\mathrm{y}_{1}}{\mathrm{~b}_{\mathrm{y}}}=\frac{\mathrm{z}-\mathrm{z}_{1}}{\mathrm{k}_{\mathrm{d}}}=\lambda
where \vec{a}=x_{1} \hat{\imath}+y_{1} \hat{l}+z_{1} \hat{k} is a point on the line and \vec{b}=b_{1} \hat{l}+b_{2} \hat{\jmath}+b_{3} \hat{k} is a vector parallel to the line.
Explanation:
Since line is drawn in the direction of \widehat{(1}+\hat{\jmath}-\widehat{2 \hat{k}}), it is parallel to (\hat{\imath}+\hat{\jmath}-2 \hat{k})
Here,  and \vec{b}=\hat{i}+-\hat{l}-2 \hat{k}