Question:
Under what condition will the lines m2 x + ny – 1 = 0 and n2x – my + 2 = 0 be perpendicular?
Under what condition will the lines m2 x + ny – 1 = 0 and n2x – my + 2 = 0 be perpendicular?
Options:
- a) mn – 1 = 0
- b) mn + 1 = 0
- c) m + n = 0
- d) m – n = 0
- a) mn – 1 = 0
- b) mn + 1 = 0
- c) m + n = 0
- d) m – n = 0
correct answer : a)
Explanation:
m1 = -m
n
2
and m2 = –
–
n
m
2
= n
m
2
for perpendicular
-×m
n
n
m
22
= -1 Þ mn – 1 = 0
m1 = -m
n
2
and m2 = –
–
n
m
2
= n
m
2
for perpendicular
-×m
n
n
m
22
= -1 Þ mn – 1 = 0