d2jsp
Log InRegister
d2jsp Forums > Off-Topic > General Chat > Homework Help > Adding Cosine And Sine
Add Reply New Topic New Poll
Views: 194Replies: 5Track Topic
Member
Posts: 2,906
Joined: Feb 28 2009
Gold: 10.00
#1
Jan 20 2014 07:35pm
How do you work through this:

cos(30*pi*t - 0.6) - cos(30*pi*t)

I think it has something to do with putting it into exponential form, but I'm not positive. I already have the answer from my book, but I don't know how the publisher found it.
Member
Posts: 10,812
Joined: Oct 15 2009
Gold: Locked
Warn: 20%
#2
Jan 20 2014 08:12pm
what "answer" did the book say...
Member
Posts: 2,906
Joined: Feb 28 2009
Gold: 10.00
#3
Jan 20 2014 08:45pm
Quote (Azrad @ Jan 20 2014 10:12pm)
what "answer" did the book say...


cos(30*pi*t - 0.6) - cos(30*pi*t) = 2sin(30*pi*t - 0.3)*sin(0.3)
Member
Posts: 35,671
Joined: Aug 11 2008
Gold: 2,130.00
#4
Jan 20 2014 09:22pm
use phasors
Member
Posts: 7,721
Joined: Oct 11 2008
Gold: 304.00
#5
Jan 21 2014 12:03am
Quote (FamilyGuyViewer @ Jan 20 2014 09:22pm)
use phasors


not for this, not really valid


Quote (SexualNinja @ Jan 20 2014 08:45pm)
cos(30*pi*t - 0.6) - cos(30*pi*t) = 2sin(30*pi*t - 0.3)*sin(0.3)




from

http://www.sosmath.com/trig/Trig5/trig5/trig5.html

This post was edited by saber_x3 on Jan 21 2014 12:04am
Member
Posts: 2,906
Joined: Feb 28 2009
Gold: 10.00
#6
Jan 21 2014 07:45am
Quote (saber_x3 @ Jan 21 2014 02:03am)
not for this, not really valid



http://www.sosmath.com/trig/Trig5/trig5/img9.gif


from

http://www.sosmath.com/trig/Trig5/trig5/trig5.html


Yes! Thank you so much! I thought I remembered reading product to sum formulas once, but idk, just couldn't remember what they were called I guess.
Go Back To Homework Help Topic List
Add Reply New Topic New Poll

© 2003-2026 d2jsp  Contact