Year 12s: what will be the first way you research your future options? >>

Trig problems need help

coconut64

How can I shows that these two expressions underlined are the same ?

thanks

Reply 1

Blazy

Original post by coconut64

How can I shows that these two expressions underlined are the same ?

thanks

You seem to have some confusion about fractions here...

Step 1) Note

\displaystyle \frac{1}{abc} = \frac{1}{a} \times \frac{1}{b} \times \frac{1}{c}

Step 2) What's the definition of

\displaystyle \sec(x)

? What about

\displaystyle \cot(x)

?

Piece them together.

Reply 2

coconut64

Original post by Blazy

You seem to have some confusion about fractions here...

Step 1) Note

\displaystyle \frac{1}{abc} = \frac{1}{a} \times \frac{1}{b} \times \frac{1}{c}

Step 2) What's the definition of

\displaystyle \sec(x)

? What about

\displaystyle \cot(x)

?

Piece them together.

I have managed to work it out from one side but not the other ...

thanks

Reply 3

bstone13

cos2y is 1/sec2y, like you said on the left. Just apply that to the RHS as well and you should be sorted - don't just change the cot term

Reply 4

Prince David

Well, you have to recall that
sec2x=1/cos2x and
cot2x=1/tan2x

Reply 5

coconut64

Original post by bstone13

cos2y is 1/sec2y, like you said on the left. Just apply that to the RHS as well and you should be sorted - don't just change the cot term

how can I get cos2y at the bottom? I only have cos^2 2y at the top of my fraction and this wouldn't give me sec2y... Thanks

Reply 6

bstone13

Original post by coconut64

how can I get cos2y at the bottom? I only have cos^2 2y at the top of my fraction and this wouldn't give me sec2y... Thanks

You have to go back to the beginning. You didn't sub in for cos2y when you should have.

Does it make sense now?

Quick Reply

Latest

Articles for you

How to revise for GCSE Maths: AQA explains what to do

What is an LLM and how could it benefit your career?

Powerful questions business students forget to ask their career advisers

Why I chose a law degree and what studying law was like

Trig problems need help

Quick Reply

Related discussions

Latest

Trending

Trending

Articles for you