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Slope and Y-intercept. Section 8.3. Learning Targets. I can find the slope of a line. I can use slope-intercept form in graphing a linear equation. Warm-up. Graph y = 2x+4. Slope.
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Slope and Y-intercept Section 8.3
Learning Targets • I can find the slope of a line. • I can use slope-intercept form in graphing a linear equation.
Warm-up • Graph y = 2x+4
Slope • The ratio that describes the tilt of a line is its slope. If a line slants upward from left to right, it has positive slope. If it slants downward, it has negative slope. To calculate slope, you use this ratio. • Slope = or
Practice • Find the slope of the line through C (-2,6) and D (4,3) • Find the slope of the line through V(8, –1) and Q(0, –7). • Find the slope of the line through S(-4, 3) and Q(-10, 9).
Y-intercept • The y-intercept of the line is the point where the line crosses the y-axis. • What would the x value be?
Slope-Intercept Form • The equation y = mx + b is the slope-intercept form In this form, m is the slope of the line, and b is the y-intercept.
Practice • Identify the slope and y-intercept of the graph of each equation. Then graph the equation. • y= 3x – 2 • y = -¾x + 1
Homework • Reteaching and Practice 8.3 • Practice 8.3 • #5 y= 5x-6 • #6 y=-7/2x + 5