Chapter 4.3, Problem 22E

To determine

To calculate: To write the equation of line that passes through the given point and is perpendicular to the given line

Answer to Problem 22E

The equation of line is $2y=x-6$

Explanation of Solution

Given: $\left(8,1\right);2y+4x=12$

Formula Used:

Equation of line passing through a point and has a known slope is given as

  $y-y_1=m\left(x-x_1\right)$ , where

  $\begin{array}{l}m=slope\\ \left(x_1,y_1\right)=po\mathrm{int}\end{array}$

When two lines are perpendicular, then the product of their slopes is equal to $-1$

Calculation:

Given the equation of line as follows:

  $\begin{array}{l}2y+4x=12\\ y+2x=6\\ y=-2x+6\end{array}$

Since the line is perpendicular to the above line, thus the slope of line is given as

  $m=-\frac{1}{m_1}$

Thus, slope of line is calculated as

  $\begin{array}{l}m=-\frac{1}{-2}\\ m=\frac{1}{2}\end{array}$

Thus, equation of line is with slope $m=\frac{1}{2}$ and passing through point $\left(8,1\right)$ calculated as follows:

  $y-y_1=m\left(x-x_1\right)$

Substituting the values in above equation:

  $\begin{array}{l}y-1=\frac{1}{2}\left(x-8\right)\\ 2\left(y-1\right)=1\left(x-8\right)\\ 2y-2=x-8\\ 2y=x-6\end{array}$

Conclusion:

Hence, the equation of lineis $2y=x-6$