I dont know how this Is equal to this: ???
J John14499 New member Joined Dec 28, 2020 Messages 1 Dec 28, 2020 #1 I dont know how this Is equal to this: ???
D Deleted member 4993 Guest Dec 28, 2020 #2 John14499 said: I dont know how thisView attachment 24055 Is equal to this: View attachment 24056 ??? Click to expand... Hint: sin(π + Θ) = -sin(Θ) and so on....
John14499 said: I dont know how thisView attachment 24055 Is equal to this: View attachment 24056 ??? Click to expand... Hint: sin(π + Θ) = -sin(Θ) and so on....
Otis Elite Member Joined Apr 22, 2015 Messages 4,414 Dec 28, 2020 #3 Hi John. Regarding the cosine terms, have you already added \(\pi + \frac{\pi}{3}\)? Do you remember the definition of an 'even' function? (Cosine is an even function.) Please let us know, if you don't understand how these hints help. ?
Hi John. Regarding the cosine terms, have you already added \(\pi + \frac{\pi}{3}\)? Do you remember the definition of an 'even' function? (Cosine is an even function.) Please let us know, if you don't understand how these hints help. ?
