This is c3 year 13 maths? Sorry i dont know the double angle formulae
If you're on edexcel, aye it's C3 and these formulae are a key part of it. They let you break down trignometric functions into more basic ones, e.g. sin(a+b)=sinacosb+sinbcosa
You should definitely cover it in class at some point so it's likely you just haven't reached the topic yet
If you're on edexcel, aye it's C3 and these formulae are a key part of it. They let you break down trignometric functions into more basic ones, e.g. sin(a+b)=sinacosb+sinbcosa
You should definitely cover it in class at some point so it's likely you just haven't reached the topic yet
That is true but this is a section 6 question which is basic trig not section 7 which is further trig so i am not expexted to use that so i need another way?
That is true but this is a section 6 question which is basic trig not section 7 which is further trig so i am not expexted to use that so i need another way?
Yes, the identity is tanA≡cosAsinA (cosA=0) and since it's an identity, it's true for all A so you can replace A with anything.
E.g. tan22=cos22sin22
or tan2θ=cosθsin2θ
Okay that makes sense thanks i worked it out now However, if there is a question where its tan^2 theta, can that equal sin^2 theta / cos ^2 theta or not?
Okay that makes sense thanks i worked it out now However, if there is a question where its tan^2 theta, can that equal sin^2 theta / cos ^2 theta or not?
Getting good at C3/4 trigonometry is all about practice. Some students think they can get by if they just learn the identities but this doesn't work. You have to try as many different questions as you can to see how/where identities can be used and to pick up all the little tricks.
When a student tells me that they hate C3 trig (common), I know that they probably haven't practiced enough
Getting good at C3/4 trigonometry is all about practice. Some students think they can get by if they just learn the identities but this doesn't work. You have to try as many different questions as you can to see how/where identities can be used and to pick up all the little tricks.
When a student tells me that they hate C3 trig (common), I know that they probably haven't practiced enough
haha i completely understand are you a teacher of maths? reccommend any good websites for tutors or even yourself?