Questions in trigonometry

Select	Question
	In triangle $ABC$ , $(b+c)\cos A+(c+a)\cos B$ $+(a+b)\cos C=$
	In $\Delta ABC,\frac{\sin B}{\sin (A+B)}=$
	In $\Delta ABC,\frac{\sin (A-B)}{\sin (A+B)}=$
	In a $\Delta ABC$ , if ${{b}^{2}}+{{c}^{2}}=3{{a}^{2}}$ , then $\cot B+\cot C-\cot A=$
	In a $\Delta ABC$ , if ${{c}^{2}}+{{a}^{2}}-{{b}^{2}}=ac$ , then $\angle B=$
	In $\Delta ABC,\left( \cot \frac{A}{2}+\cot \frac{B}{2} \right)\,\left( a{{\sin }^{2}}\frac{B}{2}+b{{\sin }^{2}}\frac{A}{2} \right)$ =
	In $\Delta ABC,$ if ${{\sin }^{2}}\frac{A}{2},{{\sin }^{2}}\frac{B}{2},{{\sin }^{2}}\frac{C}{2}$ be in H. P. then a, b, c will be in
	In $\Delta ABC,{{(a-b)}^{2}}{{\cos }^{2}}\frac{C}{2}+{{(a+b)}^{2}}{{\sin }^{2}}\frac{C}{2}=$
	In $\Delta ABC,$ if $a=16,b=24$ and $c=20,$ then $\cos \frac{B}{2}=$
	In$\Delta ABC,$ if $\cos A+\cos C=4{{\sin }^{2}}\frac{1}{2}B,$ then $a,b,c$ are in