Question

2 cos^2 13П/24 cos^2 23П/24​

Answer 1

$2Cos^{2} \frac{13\pi }{24}Cos^{2} \frac{23\pi }{24} =2Cos^{2}(\frac{\pi }{2}+\frac{\pi }{24})Cos^{2}(\pi-\frac{\pi }{24})=2Sin^{2}\frac{\pi }{24}Cos^{2}\frac{\pi }{24}=0,5Sin^{2}\frac{\pi }{12}$