How do you make a graph from an equation?

Answer 1

finding the equation of a line of (-1,2) and (1,2):

formula:

y=mx+b

m = slope

b = y intercept

first find m: m=(y2-y1)/(x2-x1)

so, m=(2-2)/ (1- -1)

m=0

since you now know m you can plug that in to the formula:

y=0x+b

to get b:

plug in the coordinates (either (-1,2) or (1,2)), it comes out the same

(-1,2). y=mx+b or 2=0 × -1+b, ==>solving for b: b=2-(0)(-1). b=2

(1,2). y=mx+b or 2=0 × 1+b, ==>solving for b: b=2-(0)(1). b=2

you now know that m=0 and b=2, now plug that back in the equation to get:

y=mx+b

y=0x+2

y+2

It's confusing, but it works!

Answer 2

It depends on what type of equation you are graphing. It is also important to know what form the function is in, whether it is standard or intercept, etc.

y=mx+b
The y-intercept is b, and mark the next point depending on the slope.

y=ax2+bx+c
Either factor it into (x-h)(x-k) or use the quadratic formula.

y=a(x-h)2+k
Point (h,k) will be the vertex and line of symmetry

Those are a few of many ways of graphing an equation. You may also randomly plug in easy x values of a y.
Or you can use a graphing calculator if your trying for a D-