Hi everyone, I'm trying to solve this limit but I'm having some issues
[math]\lim_{x \to 0} \left(\frac{\cot(a+2x)-2\cot(a+x)+ \cot(a)}{x^{2}}\right)=[/math][math]=\lim_{x \to 0} \left(\frac{\cot(a+2x)-\cot(a+x)- \cot(a+x) \cot(a)}{x^{2}}\right)[/math]
and after some calculations I've reached this point but I don't think I'm making any progress trying to solve it this way
[math]\lim_{x \to 0} \left(\frac{\cot(a+2x)\cot(a+x)-\cot(a)\cot(a+x)}{\cot(x) \times x^{2}}\right)[/math]
can someone help me continue or suggest another way of solving it
[math]\lim_{x \to 0} \left(\frac{\cot(a+2x)-2\cot(a+x)+ \cot(a)}{x^{2}}\right)=[/math][math]=\lim_{x \to 0} \left(\frac{\cot(a+2x)-\cot(a+x)- \cot(a+x) \cot(a)}{x^{2}}\right)[/math]
and after some calculations I've reached this point but I don't think I'm making any progress trying to solve it this way
[math]\lim_{x \to 0} \left(\frac{\cot(a+2x)\cot(a+x)-\cot(a)\cot(a+x)}{\cot(x) \times x^{2}}\right)[/math]
can someone help me continue or suggest another way of solving it