Hello. How to do this? How much does this equals? 2cos160*cos140*cos100
D deadmoon New member Joined Apr 27, 2013 Messages 6 Apr 27, 2013 #1 Hello. How to do this? How much does this equals? 2cos160*cos140*cos100
MarkFL Super Moderator Staff member Joined Nov 24, 2012 Messages 3,021 Apr 27, 2013 #2 I would look at using product to sum identities.
D deadmoon New member Joined Apr 27, 2013 Messages 6 Apr 27, 2013 #3 But I need to do this with reduction formulas, and I don't get how..
D Deleted member 4993 Guest Apr 27, 2013 #4 As suggested above, use: 2 * cos(A) * cos(B) = cos(A+B) + cos(A-B)
D deadmoon New member Joined Apr 27, 2013 Messages 6 Apr 28, 2013 #5 But there are three cosinuses, what to do with the last one?
D Deleted member 4993 Guest Apr 28, 2013 #6 deadmoon said: But there are three cosinuses, what to do with the last one? Click to expand... Then apply the formula again. You need to show some work - then we can guide you better.
deadmoon said: But there are three cosinuses, what to do with the last one? Click to expand... Then apply the formula again. You need to show some work - then we can guide you better.
D deadmoon New member Joined Apr 27, 2013 Messages 6 Apr 28, 2013 #7 Thanks, I've figured it out how to solve this. I have another question, does the equation sinx=sin1 has infinitely many solutions (answers) ?
Thanks, I've figured it out how to solve this. I have another question, does the equation sinx=sin1 has infinitely many solutions (answers) ?
D Deleted member 4993 Guest Apr 28, 2013 #8 deadmoon said: Thanks, I've figured it out how to solve this. I have another question, does the equation sinx=sin1 has infinitely many solutions (answers) ? Click to expand... Yes. Start a new thread with a new question.
deadmoon said: Thanks, I've figured it out how to solve this. I have another question, does the equation sinx=sin1 has infinitely many solutions (answers) ? Click to expand... Yes. Start a new thread with a new question.