Hoshi drew graphs for \(y=x\) and \(y=-x\) and noticed that the lines crossed at
right angles at the point \((0,0) .\) Then he drew graphs for \(y=x+4\) and
\(y=-x+4\) and noticed that the lines crossed at right angles again, this time
at the point \((0,4) .\) He tried one more pair, \(y=x-4\) and \(y=-x-4 .\) Once
again the lines crossed at right angles, at the point \((-4,0)\).
(Table not Copy)
Hoshi made this conjecture: 鈥淲hen you graph two linear equations and one has a
slope that is the negative of the other, you always get a right angle.鈥
a. Do you agree with Hoshi鈥檚 conjecture? Why or why not?
b. Draw several more pairs of lines that fit the conditions of Hoshi鈥檚
conjecture, with different slope values. Do your drawings prove or disprove
Hoshi鈥檚 conjecture?
c. If you think Hoshi鈥檚 conjecture is false, where do you think he made his
mistake?