Find the vector and Cartesian equations of the line passing through the points A(3, 4, -6) and B(5, -2, 7).
Find the vector and Cartesian equations of the line passing through the points A(3, 4, -6) and B(5, -2, 7).

Find the equations of the line passing through the point (1,-2,3) and parallel to the line \frac{\mathrm{x}-6}{3}=\frac{\mathrm{y}-2}{-4}=\frac{\mathrm{Z}+7}{5}. Also find the vector form of this equation so obtained.
Answer
Given: line passes through (1,-2,3) and is parallel to the line

x63=y24=z+75
\frac{x-6}{3}=\frac{y-2}{-4}=\frac{z+7}{5}

To find: equation of line in vector and Cartesian form
Formula Used: Equation of a line is
Vector form: \vec{\Gamma}=\overrightarrow{\mathrm{d}}+\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{z}}}=\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{i}+b_{2} \hat{l}+b_{3} \vec{k} is a vector parallel to the line.
Explanation:
Since the line \left(\right. say \left.L_{1}\right) is parallel to another line \left(\right. say \left.L_{2}\right), L_{1} has the same direction ratios as that of \mathrm{L}_{2}
Here, \vec{a}=\hat{i}-2 \hat{\jmath}+\mathfrak{s k}
Since the equation of L_{2} is

x63=y21=z+75b=3i^4l^+5k^
\begin{array}{l}
\frac{x-6}{3}=\frac{y-2}{-1}=\frac{z+7}{5} \\
\overrightarrow{\mathrm{b}}=3 \hat{\mathrm{i}}-4 \hat{\mathrm{l}}+5 \hat{\mathrm{k}}
\end{array}

Therefore,
Vector form of the line is:

r=ı^2ȷ^+3k^λλ(3i^4ȷ^+5k^)
\vec{r}=\hat{\imath}-2 \hat{\jmath}+3 \hat{k}-\lambda-\lambda(3 \hat{i}-4 \hat{\jmath}+\sqrt{5} \hat{k})

Cartesian form of the line is:

x13=y+24=z35
\frac{x-1}{3}=\frac{y+2}{-4}=\frac{z-3}{5}