Question

sinп/5 cos3п/10 + cosп/5 sin3п/10

Answer 1

$sin \frac{ \pi }{5} *cos \frac{3 \pi }{10} +cos \frac{ \pi }{5} *sin \frac{3 \pi }{10} =sin( \frac{ \pi }{5}+ \frac{3 \pi }{10}) =sin \frac{ \pi }{2} =1$