Shm (1 Viewer)

[Alexluby]

Just looked at this example...

x = 3 cos 2t + 4 sin 2t
= 5 cos (2t - @ ) where 0 < @ < pi/2 and tan @ = 4/3

How did x get simplified ot the second line, can anyone explain that?

Thx

 

[acmilan]

They use the auxillery method

acosA + bsinA = Rcos(A - @)

where R = sqrt(a² + b²) and tan@ = b/a

 

[Alexluby]

Thx ...

Btw, when we use the auxillary method, do we have to state stuff like "where 0 < @ < pi/2 and tan @ = 4/3"
If so, how was the range of 0 < @ < pi/2 worked out?

 

[FinalFantasy]

wtf the msg is stuffed up lol
i type a full line and half of it is cutt off