Go to www.google.com and type in "search" (yes that's right, type the word "search") and click on "I'm feeling lucky!"
You'll arrive at Windows Live Search. Now type in "search" in the Live Search page, and click the magnifying glass. You'll see that the very first result is Google!
As for Yahoo, it is the eighth result on Google's "search" results page and it doesn't even appear on Live's "search" results page!
Also try searching for "search" on www.yahoo.com!