5.7.1 Ax + By = C Form (standard form)
Remember slope intercept form? y = mx + b This equation gives a lot of information about slope and intercept Good for some real life applications Integers { . . . -3, -2, -1, 0, 1, 2, 3 . . .}
Standard Form Ax + By = C where A, B, and C are integers Where (0, ) y-intercept And Where ( , 0) x-intercept y-intercept X-intercept
Similarities Both are great for graphing equations of a line. Graph y=mx +b using slope and y-intercept Graph Ax + By = C using two intercept method.
Differences y=mx +b gives slope information which is nice for many applications we have seen, usually when time is a variable Ax + By = C gives two intercepts which is useful for other types of applications, usually when time is not a variable (maximization problems)
Finding the slope For Ax + By = C The slope is:
Graphing (problems 1-11, 15-22) Ex) x + y = 2 A = 1 B = 1 C = 2 x intercept ( , 0) (2, 0) y intercept ( 0, ) (0, 2)
Point Slope form (problems 24 – 31) Given a point and the slope: m = 6; (3, 4) Use the point slope form of the equation: y – 4 = 6(x – 3) y – 4 = 6x – 18 y – 6x = -14
Homework p. 248 1-3, 5 – 13 odd, 21 – 27 odd, 33, 35