First, the intercepts method.
(By the way, you know what intercept means right? Well, if not, it means "to run into" or "block" )
And thats what the intercepts method means. You look for the two points where the line crosses the X axis, and the Y axis.
Once you find the line, you'll find your coordinates.
A question can look like this = "3x + 4y - 12 = 0"
To find your coordinates, you want to find the value of X, then the value of Y.
To find the coordinates, first you wanna find the X axis. to find it, you just solve for x.
When you look at the diagram above, look at the point on the x axis. The X is somewhere, but the Y, will always be ZERO.
So, find the X-intercept of 3x + 4y - 12 = 0 (Remember, Y=0)
3x + 4y - 12 = 0
3x + 4(0) - 12 = 0
3x + 0 - 12 = 0
3x - 12 +12 = 0 +12
3x/3 = 12/3
x = 4 --> (4 , 0)
so now, we want to know what the coordinates of the Y axis is.Now, just like first one, Y is a number, but X will always be ZERO. So, solve for y.
3x + 4y - 12 = 0
3(0) + 4x - 12 = 0
0 + 4x - 12 = 0
4x - 12 +12 = 0 +12
4x/4 = 12/4
y = 3 --> (0 , 3)
now we can graph it onto our grid.
And that's how it's done
.
does the name look familiar? Its because the formula of the slope intercept method, includes the "slope method" and "the intercept method", and its put into one equation.
Miss Armstrong says: "By looking at the equation, you should know what the graph looks like.
Anyways, the formula is "y = mx + b
y is the y axis
m is the slope
x is the x axis
and b is the y intercept
STEP 1 = get the equation into y = mx + b form
3x + 4y - 12 = 0
3x + 4y -4y -12 = 0 -4y
(3x - 12)/-4 = (-4y) /-4
¾ x + 3 = y
STEP 2 = plot the y unit
STEP 3 = from b, find the second point using the slope method
aaaaand there you go.
homework for today was excercise 11 and 12.
please comment on my blog, i dont know if i made sense or not
next to blog is ... Natnele =)
Labels: angela, intercept method, scribe, slope intercept method
