How do you graph #y=1/2x+3#?

1 Answer
Feb 3, 2016

see explanation

Explanation:

To draw a straight line, only requires 2 points , although 3 is better as it assists with alignment of the other 2 points.

When the line crosses the y-axis the x-coord will be zero.By substituting x=0 into the equation this will give the corresponding y-coordinate,

x= 0 : y = 0+3 = 3 → ( 0 , 3 ) is 1 point.

Similarly for the line when it crosses the x-axis. y-coord will be zero

y=0 : # 1/2 x + 3 = 0 #

( multiply both sides by 2 to eliminate fraction )

hence x + 6 = 0 so x = -6 → ( - 6 , 0 ) is a 2nd point

Choose any value of x for the 3rd point , say, x = 2

x = 2 : y = 1 + 3 + 4 → ( 2 , 4 ) is a 3rd point.

Now plot ( 0 , 3 ) , ( - 6 , 0 ),(2 , 4 ) and draw a straight line through them.
Here is the graph of # y = 1/2 x + 3 #
graph{1/2x+3 [-10, 10, -5, 5]}