lim x -->0 sin (x^2)/ 3x^2
D daon2 Senior Member Joined Aug 17, 2011 Messages 1,003 Jun 13, 2012 #2 291 said: lim x -->0 sin (x^2)/ 3x^2 Click to expand... Make the substitution \(\displaystyle u=x^2\) and note that \(\displaystyle x\to 0 \iff u\to 0\) \(\displaystyle \displaystyle\lim_{x\to 0}\frac{\sin(x^2)}{3x^2} = \frac{1}{3}\lim_{u\to 0}\cdot \frac{\sin(u)}{u}\)
291 said: lim x -->0 sin (x^2)/ 3x^2 Click to expand... Make the substitution \(\displaystyle u=x^2\) and note that \(\displaystyle x\to 0 \iff u\to 0\) \(\displaystyle \displaystyle\lim_{x\to 0}\frac{\sin(x^2)}{3x^2} = \frac{1}{3}\lim_{u\to 0}\cdot \frac{\sin(u)}{u}\)
L lookagain Elite Member Joined Aug 22, 2010 Messages 3,251 Jun 13, 2012 #3 291 said: lim x -->0 sin(x^2)/(3x^2) . . . . Make sure you place grouping symbols around this denominator. Click to expand... Alternative using L'Hopital's Rule: \(\displaystyle \displaystyle\lim_{x\to 0} \dfrac{[cos(x^2)](2x)}{6x} \ = \) \(\displaystyle \displaystyle\lim_{x\to 0} \dfrac{cos(x^2)}{3} \ = \ ?\) Last edited: Jun 13, 2012
291 said: lim x -->0 sin(x^2)/(3x^2) . . . . Make sure you place grouping symbols around this denominator. Click to expand... Alternative using L'Hopital's Rule: \(\displaystyle \displaystyle\lim_{x\to 0} \dfrac{[cos(x^2)](2x)}{6x} \ = \) \(\displaystyle \displaystyle\lim_{x\to 0} \dfrac{cos(x^2)}{3} \ = \ ?\)
B biffboy New member Joined May 3, 2012 Messages 21 Jun 18, 2012 #4 291 said: lim x -->0 sin (x^2)/ 3x^2 Click to expand... =1/3limx->0 sinx^2/x^2 Hospital rule =1/3(2xcosx^2)/2x=limx->0 1/3(cosx^2)= 1/3
291 said: lim x -->0 sin (x^2)/ 3x^2 Click to expand... =1/3limx->0 sinx^2/x^2 Hospital rule =1/3(2xcosx^2)/2x=limx->0 1/3(cosx^2)= 1/3
L lookagain Elite Member Joined Aug 22, 2010 Messages 3,251 Jun 18, 2012 #5 biffboy said: =1/3limx->0 sinx^2/x^2 Hospital rule =1/3(2xcosx^2)/2x=limx->0 1/3(cosx^2)= 1/3 Click to expand... I already posted this solution using the same method right before yours, biffboy.
biffboy said: =1/3limx->0 sinx^2/x^2 Hospital rule =1/3(2xcosx^2)/2x=limx->0 1/3(cosx^2)= 1/3 Click to expand... I already posted this solution using the same method right before yours, biffboy.