How do I solve the limit of tan^2(2x) / 3x^2 as x approaches 0?

AI Thread Summary
To solve the limit of tan^2(2x) / 3x^2 as x approaches 0, it is suggested to use the identity tan(2x) = sin(2x)/cos(2x) and the known limit of sin(x)/x as x approaches 0. The key is recognizing that lim(2x → 0) tan(2x)/(2x) equals 1, allowing for the application of this limit to simplify the expression. By substituting and applying the limit, the result is found to be 4/3. This approach effectively resolves the initial confusion regarding the limit calculation.
theCandyman
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I am completely lost on where to start, any help would be appreciated:

lim (x->0) tan^2(2x) / 3x^2

I do not have any work so far, but I'm trying to find a way to get rid of the x^2 in the denominator, which so far has been fruitless.
 
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Try replacing tan(2x) with sin(2x)/cos(2x). You probably know something about the limit of sin(x)/x as x->0.
 
theCandyman said:
I am completely lost on where to start, any help would be appreciated:

lim (x->0) tan^2(2x) / 3x^2

I do not have any work so far, but I'm trying to find a way to get rid of the x^2 in the denominator, which so far has been fruitless.

This limit works fine without the aid of Mr.L'Ho^pital.
Are u 100% convinced that:
\lim_{2x \rightarrow 0} \frac{\tan{2x}}{2x} =1
??

If so,u'll be able to apply the formula above properly and get the result.

One more hint:
\lim_{x \rightarrow 0} \frac{\tan^{2} 2x}{3x^2} = \frac{4}{3} <br /> (\lim_{2x \rightarrow 0} \frac{\tan{2x}}{2x})^{2}

I hope you can take it from there.
 
Thank you both, I have my answer now.
 
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