vector

[tintincute]

hi
i'm trying to refresh my knowledge regarding vector and it seems i almost forget it.

i would like to know if this is correct

as you can see in my diagram:
cosΘ = Ax/|A|
therefore Ax = |A| cos Θ,
and similarly
Ay = |A| cos(90 - Θ) = |A| sin Θ.

anybody knows these shortcuts: SOH, CAH, TOA?
which represents for:

sin Θ = opposite/height
cos Θ = adjacent/height
tan Θ = opposite/adjacent

when can you use these? i was trying to figure out if this was also used it on this illustration? or maybe its on another topic

your help is greatly appreciated
thanks & regards

 

[tintincute]

oopss i think i figure it out now.
i was wrong,
it should be:

cos Θ = adjacent/hypotenuse not height.
sin Θ = opposite/hypotenuse not height.

that's why F here represents hypotenuse

thanks