Problem 42

Question

Describe how to write the equation of a line if two points on the line are known.

Step-by-Step Solution

Verified
Answer
To write the equation of a line with two known points, calculate the slope using the formula \(\frac{(y_2 - y_1)}{(x_2 - x_1)}\), substitute the slope and one of the points into the equation \(y = mx + c\), solve for \(c\), then write the final equation by substituting \(m\) and \(c\) with their calculated values.
1Step 1: Calculate the slope of the line
Given two points \(A(x_1, y_1)\) and \(B(x_2, y_2)\) on a line, we can calculate the slope of the line (\(m\)) using the formula: \[m = \frac{(y_2 - y_1)}{(x_2 - x_1)}\]
2Step 2: Substitute one point and the slope into the slope-intercept form
The slope-intercept form of a line's equation is \(y = mx + c\), where \(m\) is the slope and \(c\) is the y-intercept. Substitute the calculated slope and one of the points (say, \(A(x_1, y_1)\)) into this equation, giving \[y_1 = m x_1 + c\] Then, solve this equation for \(c\) to get the y-intercept.
3Step 3: Write the equation of the line
The final equation of the line will be in the form \(y = mx + c\), by substituting \(m\) and \(c\) with their calculated values.