Slopes: Measuring Steepness
Think of slope as the "steepness" of a line - just like a hill or a slide! The slope (m) tells you how much y changes when x increases by 1 unit. A positive slope means the line goes upward as you move right, while a negative slope means it goes downward.
To calculate slope between two points, use the formula: m = y2−y1/x2−x1. For example, the slope between points (2, 2) and (4, 8) is m = (8 - 2)/(4 - 2) = 6/2 = 3. This means y increases by 3 units for every 1 unit increase in x.
The slope-intercept form of a line is y = mx + b, where m is the slope and b is the y-intercept. If you know a line has slope 4 and y-intercept (0, 2), its equation is y = 4x + 2. If you have two points like (3, 4) and (4, 6), first find the slope m=2, then substitute to find b = -2, giving you y = 2x - 2.
Parallel lines have the same slope, like y = 2x - 3 and y = 2x + 5 (both have slope 2). Perpendicular lines have slopes that are opposite reciprocals - if one has slope 3, the other has slope -1/3, like y = 3x + 2 and y = -1/3x + 6.
Remember this! The slope is like a line's personality - it tells you how the line behaves. Steeper lines have larger absolute values for slope.