Questions: Homework
1. Find the equation of the line that includes (4,7) and is perpendicular to the line, y=2/5 x-1
Transcript text: Homework
1. Find the equation of the line that includes $(4,7)$ and is perpendicuar to the line, $y=\frac{2}{5} x-1$
Solution
Solution Steps
Step 1: Determine the Slope of the Given Line
The slope of the given line \( y = \frac{2}{5}x - 1 \) is \( m_{\text{given}} = \frac{2}{5} = 0.4 \).
Step 2: Calculate the Slope of the Perpendicular Line
The slope of the line that is perpendicular to the given line is the negative reciprocal of \( m_{\text{given}} \):
\[
m_{\text{perpendicular}} = -\frac{1}{m_{\text{given}}} = -\frac{1}{\frac{2}{5}} = -\frac{5}{2} = -2.5
\]
Step 3: Use the Point-Slope Form to Find the Equation
Using the point-slope form \( y - y_1 = m(x - x_1) \) with the point \( (4, 7) \):
\[
b = y_1 - m_{\text{perpendicular}} \cdot x_1 = 7 - (-2.5) \cdot 4 = 7 + 10 = 17
\]
Thus, the equation of the line can be expressed as:
\[
y = -2.5x + 17
\]
Final Answer
The equation of the line that includes the point \( (4, 7) \) and is perpendicular to the line \( y = \frac{2}{5}x - 1 \) is
\[
\boxed{y = -2.5x + 17}
\]