Graph y=2x+1, then choose 3 points above the line. Give the coordinates of each point and tell wether it is greater than, less than or equal to
2x + 1 at each point.
3 answers
for any point that you choose above the line, the y-coordinate of that point would be greater than 2x+1
Doesn't the line go on forever, so how could you choose 3 points above it?
did you draw the line.
for any line, unless it is vertical, you can be either above or below the line.
e.g. for your y = 2x + 1
consider (6,5), below above the line.
Why?
substitute the value x = 6
then y = 2(6)+1 = 13, but the y for your point was 5
since 5 < 13, the point (6,5) is below the line.
consider (3,15)
if x=3 in the equation y = 6+1 = 7
since 15 > 7, the point (3,15) is above the line.
Draw any non-vertical line on a piece of paper. Isn't there a region above that line and a region below that line no matter you imagine that line to go ??
for any line, unless it is vertical, you can be either above or below the line.
e.g. for your y = 2x + 1
consider (6,5), below above the line.
Why?
substitute the value x = 6
then y = 2(6)+1 = 13, but the y for your point was 5
since 5 < 13, the point (6,5) is below the line.
consider (3,15)
if x=3 in the equation y = 6+1 = 7
since 15 > 7, the point (3,15) is above the line.
Draw any non-vertical line on a piece of paper. Isn't there a region above that line and a region below that line no matter you imagine that line to go ??
2 answers