 injective function and image - XP Math - Forums Sign Up FREE! | Sign In | Classroom Setup | Common Core Alignment  XP Math - Forums injective function and image 10-31-2009 #1 LeroyTsruya   Join Date: Oct 2009 Posts: 1 injective function and image Hi all! i have a problem solving this: given the function g: R->R g(x) = (2x^2 - x)/(3x^2 +x + 1) I have to determine g is an injective function, and also find its image. any ideas? Thanks!   11-01-2009   #2
MAS1   Join Date: Dec 2008
Posts: 249 Quote:
 Originally Posted by LeroyTsruya Hi all! i have a problem solving this: given the function g: R->R g(x) = (2x^2 - x)/(3x^2 +x + 1) I have to determine g is an injective function, and also find its image. any ideas? Thanks!
The function g is injective if for all a and b in A, if g(a) = g(b), then a = b; that is, g(a) = g(b) implies a = b. Equivalently, if a ≠ b, then g(a) ≠ g(b).

Therefore, since g(0) = (2(0)^2 - 0)/(3(0)^2 + 0 + 1) = (0)/(1) = 0 and
g(1/2) = (2(1/2)^2 - (1/2))/(3(1/2)^2 + (1/2) + 1) = (0)/(2 1/4) = 0

then the function g(x) is not injective.

I'm not sure what you mean by image. Could you define it ?   03-16-2010 #3 jmw106462      Join Date: Feb 2010 Posts: 388 What Mas1 said. __________________ Please refrain from sending me frivolous PM's  Thread Tools Show Printable Version Email this Page Display Modes Linear Mode Switch to Hybrid Mode Switch to Threaded Mode Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is Off Forum Rules
 Forum Jump User Control Panel Private Messages Subscriptions Who's Online Search Forums Forums Home Welcome     XP Math News     Off-Topic Discussion Mathematics     XP Math Games Worksheets     Homework Help     Problems Library     Math Challenges

All times are GMT -4. The time now is 07:57 PM.

 Contact Us - XP Math - Forums - Archive - Privacy Statement - Top