Trigonometry : Solving Equations using identities (Example 1) : ExamSolutions

[EmmyFash]

thx 4 diz video :D

[roflololmao]

In another past paper question (sorry I can't find which one), you said that you couldn't divide both sides by sin(x) leaving behind something with cos, because that would get rid of some of the solutions...can you tell me what the difference is between that and this? I'm confused by it.

[qtutoringhelps]

Thanks for the video. How do you know, off-hand, that sin/cos = tan ? I mean, is this something that you got from a list of trig identities or that you've memorized? Where does it come from?

[ExamSolutions]

@qtutoringhelps One way is sin = 0pp/Hyp , cos = Adj/Hyp, so sin / cos = [Opp/Hyp] / [Adj/Hyp] = Opp / Adj = tan

[qtutoringhelps]

@ExamSolutions

Thank you!

[ARSENALTHEEDIBLE1234]

I understand it but agree with iamsopoor9 as i wouldve used the other main identity.

[iamsopoor9]

Hey, just wanted to know is there anyway of knowing what identities to use before attempting this or any trig question? I straight away went to use sin0+cos0 = 1.