To find the equation of a line that is perpendicular to another line and passing through a specific point, we can follow these steps:
- Determine the slope of the original line:
The given equation is 8x – 7y + 4 = 0. We can rewrite this equation in slope-intercept form (y = mx + b) to easily identify its slope.
Start by isolating y:
8x - 7y + 4 = 0
-7y = -8x - 4
y = (8/7)x + 4/7
From this equation, we see that the slope (m) of the original line is 8/7.
- Find the negative reciprocal of the slope:
Since we need the slope of the line that is perpendicular to the original line, we will take the negative reciprocal of 8/7.
The negative reciprocal is:
m_{perpendicular} = -7/8
- Use the point-slope form of the equation:
Now that we know the slope of the perpendicular line and the point through which it passes, we can use the point-slope form of the line equation:
y - y_1 = m(x - x_1)
In this case, (x1, y1) = (2, 4) and m = -7/8.
Substituting these values into the point-slope form gives:
y - 4 = -7/8(x - 2)
- Simplify the equation:
Distributing the slope on the right side:
y - 4 = -7/8x + 7/4
Now, add 4 to both sides to solve for y:
y = -7/8x + 7/4 + 16/4
y = -7/8x + 23/4
The equation of the line that passes through the point (2, 4) and is perpendicular to the line 8x – 7y + 4 = 0 is:
y = -7/8x + 23/4
This is the final equation in slope-intercept form.