Point-Slope Form

Point-Slope Form

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Point-Slope Equations need 2 things....

• A point

• A slope

Multiple Choice

Which of these is point-slope?

• $$y-y_1=m\left(x-x_1\right)$$

• $$y=mx+b$$

• $$Ax+By=C$$

Multiple Choice

Write an equation of the line going through the point (-4, 1) with a slope of 1/3.

• $$y-1=\frac{1}{3}\left(x+4\right)$$

• $$y+4=\frac{1}{3}\left(x-1\right)$$

• $$y-4=\frac{1}{3}\left(x+1\right)$$

• $$y+1=\frac{1}{3}\left(x-4\right)$$

What if I'm given just 2 points?

Multiple Choice

Write the equation in point-slope form for the line that contains the points

(-2, -3), (4, 3)

• y - 3 = 1(x - 2)

• y + 3 = 1(x + 2)

• y -3 = -1(x + 2)

• y + 3 = -1(x - 2)

We also learned how to transform Point-Slope equations into Slope Intercept form.

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Poll

Is this slope intercept form?

$$2y\ =4x\ +10$$  

• yes because it's $$y=mx+b$$  

• no, because there is a coefficient on the y.  You need to divide the entire equation by 2 first in order to get  $$y=mx+b$$  

Poll

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