Question

How do I graph piecewise functions?
Like f(x)= x+2 if x greater/equal than 0
x less than 0

Also, how do I write an equation of the line passing through (2,1) and is perpendicular to the line y= 1/2x+1

Answer 1

You graph it in two regions
1) less than zero
2) from zero toward +inf.


You know the slope of the perpendicular line is -2 (the negative reciprocal of 1/2).

y=mx+b
y=-2x+b
Put in the point 2,1, and solve for b.
then you have slope and b, so you know the equation.

Answer 2

You helped a LOT on the second question, I forgot to change it to the negative reciprocal, so thanks! I can do the second one now. But I'm still not sure about the top question. I'm not sure how do graph piecewise functions. When you say from 0, do you mean from the origin?

Answer 3

f(x)={-x+3, if x <1