Precalculus: Mathematics for Calculus, 7th Edition

Published by Brooks Cole
ISBN 10: 1305071751
ISBN 13: 978-1-30507-175-9

Chapter 1 - Section 1.10 - Lines - 1.10 Exercises - Page 115: 80

Answer

$m_{AB}\times m_{AC}=-1$ So it is right triangle.

Work Step by Step

We know, that two lines are perpendicular if and only if $m_1m_2=-1$ (as described earlier in this chapter). Using this we can find whether or not these points correspond to vertices. As the legs of a right triangle are perpendicular to each other, multiplying them should give us $-1$ (We need two, out of three possible sides to be perpendicular). See the image above for a better visualization. $m_{AB}=\frac{3-(-1)}{3-(-3)}=\frac{4}{6}=\frac{2}{3}$ $m_{BC}=\frac{8-3}{-9-3}=\frac{5}{-12}=-\frac{5}{12}$ $m_{AC}=\frac{8-(-1)}{-9-(-3)}=\frac{9}{-6}=-\frac{3}{2}$ We can clearly see, that: $m_{AB}\times m_{AC}=\frac{2}{3}\times (-\frac{3}{2})=-1$ So, it is right triangle.
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.