4 2 Plot Points Graph Functions fguilbert orrhs

4. 2 Plot Points Graph Functions. fguilbert orrhs

10 = 2 X 1 variable This equation has only 1 answer. 5=X Y=2 X-1 fguilbert orrhs 2 variables many answers

Graph Y = 2 X 1 X Y 2(-2) 1= -5 -5 -2 -1 0 2 (0) - 1 = -1 2 3 2 (2) - 1 = 3 To graph, make a table of fguilbert orrhs

Y = 2 X -1 Plot each point. X -2 0 2 fguilbert orrhs Y -5 -1 3

y = 2 x -1 Every point on the line is a solution to the equation. Is (3, 5) a solution? fguilbert orrhs Does (3, 5) make the equation true?

y = 2 X - 1 5 = 2 (3) - 1 5=6 -1 5 = 5 true fguilbert orrhs Try ( 3, 5 ) X Y

Make a table Pick 3 values for X. Find Y X Y y = x + 2 -3 -1 ( -3 ) + 2 = -1 0 2 0) + 2 = 2 ( 2 4 ( 2) + 2 = 4 fguilbert orrhs

Y=X+2 fguilbert orrhs X -3 0 Y -1 2 2 4

Y=X+2 Is ( -2, 1 ) a solution? Substitute. 1 = -2 + 2 1= 0 not a solution fguilbert orrhs

1 Y =3 X + 1 What numbers X Y are the best -3 choice for X? 0 Multiples 3 of 3 fguilbert orrhs

1 Y =3 X + 1 X Y 1 ( -3 ) + 1 = 0 3 -3 0 1 = 1 ( 0 ) + 1 1 0 3 2 1 (3)+1 =2 3 3 fguilbert orrhs

Pool Costs Swimming Pool Fees Family $60 Guests fguilbert orrhs $5 per visit

Write an equation. C is annual cost. g is # guests g C 0 60 1 65 2 70 3 3 75 fguilbert orrhs 60 + 5 g = C 60 + 5 (0) 60 + 5 (1) 60 + 5 (2) 60 + 5 (3)

g C 0 1 2 3 60 65 70 75 g is the domain. { 0 , 1, 2, 3, …} C is the range { 60, 65, 70, 75, …} Cost is a function … … of # guests. Put domain on horizontal axis. Put range on vertical axis. fguilbert orrhs

g 0 1 2 3 … C 60 65 70 75 … fguilbert orrhs C O S T 90 80 70 60 . . . 0 2 4 6 8 guests

Halloween joke for the day. Why didn’t the skeleton want to go to school? His heart wasn’t in it. fguilbert orrhs