5 lb - Pg 385 , ques-50

[piyushagrawal4]

Hello,

Even i found an error in question 50, chapter 9.Pg 385). I agree with the answer (C), but why can't (E) also be an answer.

We get , from (C) that :
kn + lm > (mn)^2
and, (mn)^2 >= 0

so, it means that:
kn + lm > 0
i.e. kn > -lm
which is indeed (E)

Therefore, (E) is also a possible answer

[tommywallach]

Hey Piyush,

Looks like you're right! This goes to errata! Well done.

-t