Questions in fun-lim

Select	Question
	If $f(a)=2,\ f'(a)=1,\ g(a)=-1;\ g'(a)=2$ , then $\underset{x\to a}{\mathop{\lim }}\,\frac{g(x)f(a)-g(a)f(x)}{x-a}=$
	$\underset{x\to \alpha }{\mathop{\lim }}\,\frac{\sin x-\sin \alpha }{x-\alpha }=$
	$\underset{x\to \infty }{\mathop{\lim }}\,\frac{\sqrt{{{x}^{2}}+{{a}^{2}}}-\sqrt{{{x}^{2}}+{{b}^{2}}}}{\sqrt{{{x}^{2}}+{{c}^{2}}}-\sqrt{{{x}^{2}}+{{d}^{2}}}}=$
	$\underset{x\to \pi /2}{\mathop{\lim }}\,\frac{2x-\pi }{\cos x}=$
	$\underset{x\to 0}{\mathop{\lim }}\,\frac{\sin x-x}{{{x}^{3}}}=$
	$\underset{h\to 0}{\mathop{\lim }}\,\frac{{{(a+h)}^{2}}\sin (a+h)-{{a}^{2}}\sin a}{h}=$
	$\underset{x\to 3}{\mathop{\lim }}\,\left\{ \frac{x-3}{\sqrt{x-2}-\sqrt{4-x}} \right\}=$
	$\underset{x\to 0}{\mathop{\lim }}\,\frac{x\cos x-\sin x}{{{x}^{2}}\sin x}=$
	$\underset{x\to \infty }{\mathop{\lim }}\,\frac{(x-1)(2x+3)}{{{x}^{2}}}=$
	$\underset{x\to \infty }{\mathop{\lim }}\,\left[ \frac{{{1}^{3}}+{{2}^{3}}+{{3}^{3}}+.......+{{n}^{3}}}{{{n}^{4}}} \right]=$