Question

sin(pi/10).sin(3pi/10)​

Answer 1

Answer:

0.25

Step-by-step explanation:

sin(π/10)=(√5-1)/4

sin(3π/10)=cos(2π/10)=(√5+1)/4

So

sin(π/10)*sin(3π/10)=(√5-1)*(√5+1)/16

=(5-1)/16=1/4=0.25

Hope it helps.