The period of the function $f(x)=\frac{2 \sin \left(\frac{\pi x}{3}\right) \cos \left(\frac{2 \pi x}{5}\right)}{3 \tan \left(\frac{7 \pi x}{2}\right)-5 \sec \left(\frac{5 \pi x}{3}\right)}$ is

If $A+B+C=4 S$, then $\sin (2 S-A)$

$$ +\sin (2 S-B)+\sin (2 S-C)-\sin 2 S= $$

If $1^{\circ}=0.0175$ radians, then the approximate value of $\sec 58^{\circ}$ is