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Warm_Up. Identify the x and y-intercepts: 2 x + 3 y = 9 y = 5 x – 10 3. Is this graph below symmetrical on the x-axis, y-axis, and/or origin?. _Assignment. 9/17/2014 9:06:59 AM. 2-4: _Writing Linear Equations. 2. _Writing Linear Functions. Section 2-4 Section 2-4 Section 2-4.
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2-4: _Writing Linear Equations Warm_Up Identify the x and y-intercepts: • 2x + 3y = 9 • y = 5x – 10 3. Is this graph below symmetrical on the x-axis, y-axis, and/or origin?
_Assignment 9/17/2014 9:06:59 AM 2-4: _Writing Linear Equations 2
_Writing Linear Functions Section 2-4 Section 2-4 Section 2-4 2-4: _Writing Linear Equations
2-4: _Writing Linear Equations _Definitions • Linear equation: An equation whose graph is a line • Slope is a non-vertical line of the vertical change to the horizontal change between two points of a line • Y-intercept is where the line crosses the y-axis
2-4: _Writing Linear Equations _Slope Equation Slope equation: Rewrite it as: Rise: The number of points up (horizontally) from the previous point Run:The number of points sideways (vertically) from the rise
2-4: _Writing Linear Equations _Types of Slope Negative Slope Positive Slope
2-4: _Writing Linear Equations _Types of Slope Zero Slope Horizontal Line
2-4: _Writing Linear Equations _Types of Slope No Slope/ Undefined Vertical Line
2-4: _Writing Linear Equations _Slope-Intercept Form • Slope-Intercept form: • How do we know if it linear? • If the ∆y is the SAME in the change difference Slope Y-intercept
2-4: _Writing Linear Equations _Steps Steps for slope given as point(s): • Find the change of Y and change of X of two of the points • Determine the ratios for both • Make sure the equation is linear by checking two different points • Simplify and reduce the fraction • Check answer using graphing calculator
2-4: _Writing Linear Equations _Example 1 What is the slope of this? Create a t-chart & solve for slope 3-(-2) = 5 –1-(2) = -3
2-4: _Writing Linear Equations _Example 1 What is the slope of this? –2 3 –1 2
2-4: _Writing Linear Equations _Example 2 What is the slope of this?
2-4: _Writing Linear Equations +2 +2 +2 –1 –1 –1 _Your Turn What is the slope of this?
2-4: _Writing Linear Equations _Example 3 What is the slope of this?
2-4: _Writing Linear Equations _Slope-Intercept Form • Slope-Intercept form: • X is the x-coordinate • Y is the y-coordinate • M is the slope Slope Y-intercept
2-4: _Writing Linear Equations _Steps in Slope-Intercept Form • Identify the given • Plug into y = mx + b • Simplify
2-4: _Writing Linear Equations _Example 4 Write an equation where the slope is 2 and the y-intercept is (0, –2)
2-4: _Writing Linear Equations _Example 5 Write an equation where the slope is 1/4 and the y-intercept is (0, 3)
2-4: _Writing Linear Equations _Your Turn Write an equation where the slope is zero and the y-intercept is (0,–2)
2-4: _Writing Linear Equations _Example 6 Write an equation where the slope is undefined and has a point of (1, 2)
2-4: _Writing Linear Equations _Point-Slope Form Point-Slope Form • M is the slope • X1 is the X-Coordinate • Y1 is the Y-Coordinate
2-4: _Writing Linear Equations _Example 7 Determine an equation of the line with slope of 4 and containing the point (1, 2)
2-4: _Writing Linear Equations _Example 8 Determine an equation of the line with slope of -4/3 and containing the point (-3, 2)
2-4: _Writing Linear Equations _Your Turn Determine an equation of the line with slope of –2/5 and containing the point (7,–2)
2-4: _Writing Linear Equations _Example 9 Determine an equation of the line containing the points (2, 3) and (-4, 5)
2-4: _Writing Linear Equations _Your Turn Determine an equation of the line containing the points (3, 12) and (6, 27)
2-4: _Writing Linear Equations _Assignment Pg 191: 37-49 odd, 48, 50