214k views
2 votes
How do I complete this identity? sin(2θ) sin(4θ) cos(2θ) cos(4θ) = ?

1 Answer

6 votes

Answer:

  • sin(20) sin(40) cos(40) cos(20)
  • [sin(20)*cos(20)]*[sin(40)*cos(40)]
  • [sin(2*20)/2]*[sin(2*40)/2]
  • [sin(40)*sin(80)]/2

User Tautvydas
by
4.3k points