# Conditions for which inequalitys is true

A:
1-mt<w^2(m+t)

B:
-(1+mt)<(w^2 )t(m-t)

i have 4 cases
for each case they said that needs to be a condition for which this case would be true
1: m>t and mt<1
so they say that i have to demand
w^2>(1-mt)/(m+t) which is inequality A

2: m<t and mt<1
they say that i have to demand
inequalitys A and B

why ??

## Answers and Replies

HallsofIvy
Homework Helper
A:
1-mt<w^2(m+t)

B:
-(1+mt)<(w^2 )t(m-t)

i have 4 cases
for each case they said that needs to be a condition for which this case would be true
1: m>t and mt<1
so they say that i have to demand
w^2>(1-mt)/(m+t) which is inequality A

2: m<t and mt<1
they say that i have to demand
inequalitys A and B

why ??
If m< t, m- t is negative, if m> t, m- t is positive, if mt< 1, 1-mt is positive and w^2 is always positive.

so why in case two they demand both ??
it seems like the left side is true always
it cannot be negative?

why in the 1st case we only pick only one innequality
??

even if i substitute what you say regarding the positive and negative
i get
positive>positive

so??

wwoowww thanks i understood that stuff
:)