Register to reply

Multiplying the two inequalities

Share this thread:
Mar12-14, 03:26 PM
P: 71
Lets suppose we have two inequalities,
First inequality is x-y≤a-b≤x+y
Second inequality is t-g≤c-d≤t+g How can I multiply these inequalities

Phys.Org News Partner Mathematics news on
Heat distributions help researchers to understand curved space
Professor quantifies how 'one thing leads to another'
Team announces construction of a formal computer-verified proof of the Kepler conjecture
Mar12-14, 03:55 PM
Sci Advisor
P: 6,062
What do you have in mind by multiplying inequalities? In any case if all the terms are positive then term by term multiplication is OK. Otherwise be very careful.
Mar13-14, 12:08 PM
P: 71

Mar16-14, 07:36 AM
Sci Advisor
HW Helper
PF Gold
P: 12,016
Multiplying the two inequalities

If you do not know whether these expressions can be negative, you can't validly multiply inequalities into new inequalities.

If you DO know that all the 8 individual numbers are, say, positive, you may first rearrange your inequalities, to for example:
x+b<=a+y<=x+2y+b and THEN multiply with the similary rearranged second inequality.

Register to reply

Related Discussions
Multiplying by dX Calculus 8
Multiplying a 3 by 3 matrix Calculus & Beyond Homework 3
Multiplying Fractions Introductory Physics Homework 1
Multiplying by dx Differential Equations 25
Multiplying by 2 Fun, Photos & Games 6