- #1
SpringPhysics
- 107
- 0
Homework Statement
Prove that any side of a triangle is less than or equal to the sum of the other two sides of the triangle (using components).
Homework Equations
root [(x3-x1)^2 + (y3-y1)^2]
<= root [(x2-x1)^2 + (y2-y1)^2] + root [(x3-x2)^2 + (y3-y2)^2]
The Attempt at a Solution
I attempted to solve the inequality portion by considering the slopes of the sides of the triangle (using components), where
[(x2-x1)/(y2-y1)]^2 + [(x2-x1)/(y2-y1)]^2 + [(x2-x1)/(y2-y1)]^2 > 0
I expanded everything but that got really messy. We haven't learned to really prove anything so far (but the textbook only mentions the distance formula), so I don't really know where to start with the problem. Our professor showed us a method that involved squaring differences of numbers in order to prove something (and taking the discriminant), but it doesn't seem to be viable here.