If $\frac{x^2+1}{\left(x^2+2\right)\left(x^2+3\right)}=\frac{A x+B}{x^2+2}+\frac{C x+D}{x^2+3}$, then $A+B+C+D=$

If $2 \sin \theta+3 \cos \theta=2$ and $\theta \neq(2 n+1) \frac{\pi}{2}$, then $\sin \theta+\cos \theta=$

If $\sin A=-\frac{24}{25}, \cos B=\frac{15}{17}, A$ does not belong to 4th quadrant and $B$ does not belong to 1st quadrant, then $(A+B)$ lies in the quadrant

$$ 4 \cos \frac{7 \theta}{2} \cos \frac{3 \theta}{2} \sin 5 \theta= $$