Prove that, cos20° cos40° cos80°=$\frac{1}{8}$
Prove that, cos20° cos40° cos80°=$\frac{1}{8}$ Solution: cos20° cos40° cos80° = $\frac{1}{2}$ (2 cos20° cos40°) cos80° = $\frac{1}{2}$ {cos (20°+40°) + …
Prove that, cos20° cos40° cos80°=$\frac{1}{8}$ Solution: cos20° cos40° cos80° = $\frac{1}{2}$ (2 cos20° cos40°) cos80° = $\frac{1}{2}$ {cos (20°+40°) + …