C3 Trigs

Original post by sabahshahed294

http://www.madasmaths.com/archive/iygb_practice_papers/c3_practice_papers/c3_h.pdf

Need help in Question 9.I applied the tan(2theta) identity and found cot(2theta) through it but I don't really get what to do next.
Thanks in Advance!

You know, for example that

\tan 4\theta = \frac{2\tan 2\theta}{1 - \tan^2 2\theta}

and that

\cot 2\theta = \frac{1}{\tan 2\theta}

, so you can simplify

\cot 2\theta \tan 4\theta

nicely.

Can you take it from here?

Reply 4

OP

Original post by Zacken

You know, for example that

\tan 4\theta = \frac{2\tan 2\theta}{1 - \tan^2 2\theta}

and that

\cot 2\theta = \frac{1}{\tan 2\theta}

, so you can simplify

\cot 2\theta \tan 4\theta

nicely.

Can you take it from here?

Yes, I could. Thank you! :smile:

Reply 5

OP

Original post by B_9710

Find

\tan 4\theta

by using the identity which you have already used (pretty much)

\displaystyle \tan 4\theta =\frac{2\tan 2\theta }{1-\tan^ 2\theta }

.

Yup done.

Thanks for your time :smile:

It's 1-tan² (2theta) btw.

Reply 6

Original post by sabahshahed294

Yes, I could. Thank you! :smile:

Great!

Reply 7

OP

Original post by Zacken

Great!

Btw, Congratulations on your results(I know it's late :tongue:

but I saw now. haha) :smile:

Pretty cool! :h:

Which subject did you get an A in? (If you don't mind me asking. )

Reply 8

Original post by sabahshahed294

Btw, Congratulations on your results(I know it's late :tongue:

but I saw now. haha) :smile:

Pretty cool! :h:

Which subject did you get an A in? (If you don't mind me asking. )

Thank you very much! Did you get any results as well - AS or GCSE?

I ended up with A*A*A in M, FM and Physics respectively. :smile:

Reply 9

OP

Original post by Zacken

Thank you very much! Did you get any results as well - AS or GCSE?

I ended up with A*A*A in M, FM and Physics respectively. :smile:

Wow. Awesome! :biggrin:

I did my A2 this year.Did Physics, Chemistry and Maths this year but I couldn't do well in some units such as C34, Physics 5,Physics 6 and Chemistry 5 :frown:

(I'm an International Student so I'll be reappearing for C34 and Chemistry 5 in January.) Rest of the A2 Units I got A's :smile:

except for a B in Physics 4 :tongue:

. I hate A Level Physics a lot lol.(Especially Edexcel, I did CIE for IGCSEs which was far better than this) :tongue:

(edited 7 years ago)

Reply 10

Original post by sabahshahed294

Wow. Awesome! :biggrin:

I did my A2 this year.Did Physics, Chemistry and Maths this year but I couldn't do well in some units such as C34, Physics 5,Physics 6 and Chemistry 5 :frown:

(I'm an International Student so I'll be reappearing for C34 and Chemistry 5 in January.) Rest of the Units I got A's :smile:

except for a B in Physics 4 :tongue:

. I hate A Level Physics a lot lol.(Especially Edexcel, I did CIE for IGCSEs which was far better than this) :tongue:

Oh right, of course! Now I remember! Well done nevertheless and good luck for Jan! Are you applying to the UK for uni? :smile:

Reply 11

OP