Point Slope Formula:
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The point-slope form is a way to express the equation of a line when you know the slope and one point on the line. It's particularly useful in algebra and calculus for writing linear equations quickly.
The calculator uses the point-slope formula:
Where:
Explanation: The equation shows that the difference in y-values between any point (x,y) and the known point (x₁,y₁) is proportional to the difference in x-values, with the slope as the constant of proportionality.
Details: Point-slope form is essential in algebra for quickly writing equations of lines, especially when given a point and slope. It's also useful for finding tangent lines in calculus and modeling linear relationships in various fields.
Tips: Enter the slope (m) of your line and the coordinates (x₁,y₁) of a point the line passes through. The calculator will provide both the point-slope form and the slope-intercept form of the equation.
Q1: When should I use point-slope form?
A: Use it when you know the slope of a line and one point it passes through, especially when you need to quickly write an equation.
Q2: How is this different from slope-intercept form?
A: Slope-intercept form (y = mx + b) shows the slope and y-intercept explicitly, while point-slope form shows the relationship between any point and a specific known point.
Q3: Can I use this with two points instead of slope and point?
A: Yes, but you'd need to calculate the slope first using (y₂ - y₁)/(x₂ - x₁) before using the point-slope form.
Q4: What if my slope is zero or undefined?
A: For zero slope (horizontal line), the equation simplifies to y = y₁. For undefined slope (vertical line), it becomes x = x₁.
Q5: How do I graph using point-slope form?
A: Plot the known point (x₁,y₁), then use the slope to find additional points by moving up/down (numerator) and left/right (denominator) from that point.