Jameson Insights Author Gold Member MHB Messages 4,533 Reaction score 13 Thread starter Nov 10, 2013 #1 Which is larger? $\sqrt{7}-\sqrt{6}$ or $\sqrt{6}-\sqrt{5}$? Answer without using a calculator. --------------------
Which is larger? $\sqrt{7}-\sqrt{6}$ or $\sqrt{6}-\sqrt{5}$? Answer without using a calculator. --------------------
Jameson Insights Author Gold Member MHB Messages 4,533 Reaction score 13 Nov 17, 2013 #2 Congratulation to the following members for their correct solutions: 1) MarkFL 2) anemone 3) Pranav 4) eddybob123 5) kaliprasad Solution (from eddybob123): Spoiler $$ 5041 > 5040$$ $$\Rightarrow 71>2\sqrt{1260}$$ $$\Rightarrow 1< 72-2\sqrt{1260}$$ $$\Rightarrow 1^2< (\sqrt{42}-\sqrt{30})^2$$ $$\Rightarrow 1< \sqrt{42}-\sqrt{30}$$ $$\Rightarrow 2<2(\sqrt{42}-\sqrt{30})$$ $$\Rightarrow 7-2\sqrt{42}+6<6-2\sqrt{30}+5$$ $$\Rightarrow (\sqrt{7}-\sqrt{6})^2<(\sqrt{6}-\sqrt{5})^2$$ $$\Rightarrow \sqrt{7}-\sqrt{6}<\sqrt{6}-\sqrt{5}$$
Congratulation to the following members for their correct solutions: 1) MarkFL 2) anemone 3) Pranav 4) eddybob123 5) kaliprasad Solution (from eddybob123): Spoiler $$ 5041 > 5040$$ $$\Rightarrow 71>2\sqrt{1260}$$ $$\Rightarrow 1< 72-2\sqrt{1260}$$ $$\Rightarrow 1^2< (\sqrt{42}-\sqrt{30})^2$$ $$\Rightarrow 1< \sqrt{42}-\sqrt{30}$$ $$\Rightarrow 2<2(\sqrt{42}-\sqrt{30})$$ $$\Rightarrow 7-2\sqrt{42}+6<6-2\sqrt{30}+5$$ $$\Rightarrow (\sqrt{7}-\sqrt{6})^2<(\sqrt{6}-\sqrt{5})^2$$ $$\Rightarrow \sqrt{7}-\sqrt{6}<\sqrt{6}-\sqrt{5}$$