Graph: Y=2x-7
- Thread starter EORTIZ40
- Start date
I think my way is actually easier.
-7 is the X-intercept
2X is the slope
Make a point at (-7,0)
The slope is 2/1 and it's positive so you go up 2 and right 1
Make a line
1. Find the domain
2. Find the intercepts by x=0, so y=-7 and vice versa y=0 x=7/2
3. Symmetry (even/odd function) f(-x)
4. Asymptotes
- vertical (find a value that provides non 0 in the numerator and 0 in denominator)
- horizontal (limit as x tend to +/- infinity)
- oblique (by long division, if appropriate)
And be aware that polynomial functions don't have asymptotes!!
5. Increasing/decreasing intervals, max/min and critical points by finding the first derivative
6. Concavity, point of inflection (if occur) by finding the second derivative
7. Sketch the graph by plotting all the points
2. Find the intercepts by x=0, so y=-7 and vice versa y=0 x=7/2
3. Symmetry (even/odd function) f(-x)
4. Asymptotes
- vertical (find a value that provides non 0 in the numerator and 0 in denominator)
- horizontal (limit as x tend to +/- infinity)
- oblique (by long division, if appropriate)
And be aware that polynomial functions don't have asymptotes!!
5. Increasing/decreasing intervals, max/min and critical points by finding the first derivative
6. Concavity, point of inflection (if occur) by finding the second derivative
7. Sketch the graph by plotting all the points
Scorpy, I understand you wanting to help, but someone that asks how to graph y=2x-7 is not going to understand all the info you mention above.
I think my way is actually easier.
-7 is the X-intercept
2X is the slope
Make a point at (-7,0)
The slope is 2/1 and it's positive so you go up 2 and right 1
Make a line
I understand your desire to help, Semo....but what you have said here is quite simply incorrect, and will probably only serve to confuse the original poster.
Please review the "slope-intercept form" for the equation of a line. The "intercept" in that equation is the y-intercept, not the x-intercept.
I think to understand this you should first understand the basic equation for a straight line:
y = m x + c
(or)
y = m x + b
(c and b are the same thing, it's just a different way of representing the y intercept)
1. m is the gradient or slope; you find m by dividing the rise by the run.
2. x is the x coordinate of the specific point on the line; you can say x or y is a number and use it to find a random point on the line.
3. c is the y intercept; the value of y when x is equal to 0.
Just think of the equation as if it is algebra; you need to figure out the value of y based off what the x is or vice versa.
y = m x + c
(or)
y = m x + b
(c and b are the same thing, it's just a different way of representing the y intercept)
1. m is the gradient or slope; you find m by dividing the rise by the run.
2. x is the x coordinate of the specific point on the line; you can say x or y is a number and use it to find a random point on the line.
3. c is the y intercept; the value of y when x is equal to 0.
Just think of the equation as if it is algebra; you need to figure out the value of y based off what the x is or vice versa.
- Joined
- Jun 18, 2007
- Messages
- 26,708
Why are you responding to a 8+ year old thread!!I think to understand this you should first understand the basic equation for a straight line:
y = m x + c
(or)
y = m x + b
(c and b are the same thing, it's just a different way of representing the y intercept)
1. m is the gradient or slope; you find m by dividing the rise by the run.
2. x is the x coordinate of the specific point on the line; you can say x or y is a number and use it to find a random point on the line.
3. c is the y intercept; the value of y when x is equal to 0.
Just think of the equation as if it is algebra; you need to figure out the value of y based off what the x is or vice versa.
jonah2.0
Full Member
- Joined
- Apr 29, 2014
- Messages
- 476
Beer soaked comment follows.
May need some ketchup ... beg your pardon; a question mark I mean.
Steven G
Elite Member
- Joined
- Dec 30, 2014
- Messages
- 12,193
You pick any three x-values, maybe 0, 1 and 2. One by one, you double the x-value and then subtract 7. This will give you the y-value for the corresponding x-value.
For example: if x=9. After doubling it you get 18. after subtracting 7 you get 11. Therefore a point on the line would be (9,11). Do the same for two more x-values and plot the three points. If you made no mistake the points will lie on a straight line. Draw the line.
For example: if x=9. After doubling it you get 18. after subtracting 7 you get 11. Therefore a point on the line would be (9,11). Do the same for two more x-values and plot the three points. If you made no mistake the points will lie on a straight line. Draw the line.