Presentation on theme: "Do Now 1. If f(x) = │(x² – 50)│, what is the value of f(-5) ?"— Presentation transcript:
1Do Now 1. If f(x) = │(x² – 50)│, what is the value of f(-5) ? A B C. 0 D E. -752. ( √2 - √3 )² =A √6 B. 5 - √6 C √6 D. 1 - √2 E. 1=A B C D E. 226
2P.3 Lines in the Plane SWBAT 1. Find the slope of a line. 2. Write linear equations given points on lines and their slopes.3. Use slope-intercept forms of linear equations to graph lines.4. Use slope to identify parallel and perpendicular lines.
3The slope of a lineSlope: rise over run, the change in y over the change in x
4The slope of a line Finding slope given 2 points: 1. (-2, 0) and (3, 1)2. (-1, 2) and (2, 2)3. (3, 4) and (3, 1)
5The point-slope form of a line Point-slope form: y – y1 = m(x – x1)Find an equation of the line that passes through the point (1, -2) and has a slope of 3.Find an equation of the line that passes through (2, - 3) and (4, 5).
6Using point-slope to create linear models During 1997, Barnes and Noble’s net sales were $2.8 billion, and in 1998 net sales were $3.0 billion.1. Write a linear equation giving the net sales y in terms of the year x.2. Use the equation to estimate the net sales during
7Linear extrapolation: an approximation in which the estimated point lies outside of the given points Linear interpolation: the estimated point lies between the two given points
8Sketching graphs of lines Slope-intercept form: y = mx + bBetter suited to graph linear equations
9Sketching graphs of lines Determine the slope and y-intercept of each linear equation and describe its graph.1. x + y = 22. y = 2
10Parallel Lines Parallel lines: have slopes that are equal Find the slope-intercept form of the equation of the line that passes through the point (2, -1) and is parallel to the line 2x – 3y = 5.
11Perpendicular LinesPerpendicular lines: have slopes that are negative reciprocalsFind an equation of the line that passes through the point (2, -1) and is perpendicular to the line x – 3y = 5.