© examsiri.com
Question : 68 of 120
Marks:
+1,
-0
Solution:
Let
OA=2i+4j−k,OB=4i+5j+k and
OC=3i+6j−3k Now,
AB=OB−OA=2i+j+2k AB=|2i+j+2k|=√4+1+4=√9=3
βC=OC−OB=−i+j−4k BC=|−i+j−4k|=√1+1+16=√18=3√2
CA=OA−OC=−i−2j+2k CA=|−i−2j+2k|=√1+4+4=√9=3
BC2=AB2+CA2 (by Pythagoras theorem) Now.
⇒(3√2)2=(3)2+(3)2⇒18=18 So, triangle is isosceles right angled triangle.
© examsiri.com
Go to Question: