My Math Forum Help me with 2 Lim tasks

 Pre-Calculus Pre-Calculus Math Forum

November 18th, 2017, 08:06 AM   #1
Newbie

Joined: Nov 2017
From: Lithuania

Posts: 1
Thanks: 0

Help me with 2 Lim tasks

Hello there. Could someone help me, and explain how these 2 tasks should be done. I added them in attachment. I know how to do simple lim tasks, but these ones are more complicated and I'm really not best at math.

Thank You.
Attached Images
 math problem.jpg (15.5 KB, 2 views)

 November 18th, 2017, 08:25 AM #2 Global Moderator   Joined: Dec 2006 Posts: 20,104 Thanks: 1907 The first limit is easily found by use of de l'HÃ´pital's rule. For a proof that doesn't rely on calculus, the method suggested by v8archie below is best. Thanks from topsquark and v8archie Last edited by skipjack; November 18th, 2017 at 09:30 AM.
 November 18th, 2017, 08:32 AM #3 Math Team   Joined: Dec 2013 From: Colombia Posts: 7,560 Thanks: 2561 Math Focus: Mainly analysis and algebra First one: multiply by $$\frac{\sqrt{7+4x}+\sqrt{7-x}}{\sqrt{7+4x}+\sqrt{7-x}} \cdot \frac{\sqrt{3+x}+\sqrt{3+2x}}{\sqrt{3+x}+\sqrt{3+2 x}}$$ Second one: write $2x-1=1+2(x-1)$ and use $$\lim_{t \to 0} (1+at)^{\frac1t}=e^a$$ Thanks from topsquark

 Thread Tools Display Modes Linear Mode

 Similar Threads Thread Thread Starter Forum Replies Last Post Zman15 Algebra 6 May 14th, 2015 05:51 AM Asy Calculus 9 January 4th, 2012 11:33 AM guy Algebra 1 March 15th, 2009 07:00 PM Stephanie91 Algebra 2 February 6th, 2009 01:12 PM

 Contact - Home - Forums - Cryptocurrency Forum - Top