A LevelMathsCambridge (CIE)Pure 3Revision NotesTrigonometryReciprocal Trigonometric FunctionsIdentities with Reciprocal Trigonometric Functions

Identities with Reciprocal Trigonometric Functions (Cambridge (CIE) A Level Maths): Revision Note

Exam code: 9709

Roger B

Author

Roger B

Last updated

Cambridge (CIE) Maths: Pure 3OCR Maths A: PureAQA Maths: PureEdexcel Maths: Pure

Did this video help you?

Trigonometry - Further Identities

What identities do I need to know with secant, cosecant, and cotangent?

  • There are two identities with sec, cosec and cot that you need to know and be able to use:

    • tan2x + 1 ≡ sec2x

    • 1 + cot2x ≡ cosec2x

  • These are not really 'new' identities – they can both be derived from sin2x + cos2x ≡ 1

    • To derive the identity for sec2x  divide  sin2x + cos2x ≡ 1  by cos2x

    • To derive the identity for cosec2x  divide  sin2x + cos2x ≡ 1  by sin2x

Trig Fur IDs Illustr 1, A Level & AS Maths: Pure revision notes

Examiner Tips and Tricks

  • These identities are not given in the exam formulae booklet – make sure you know how to find them. 

  • They will be needed to prove some trigonometric identities and solve some trigonometric equations.

Worked Example

Trig Fur IDs Example, A Level & AS Maths: Pure revision notes

You've read 1 of your 5 free revision notes this week

Unlock more, it's free!

Join the 100,000+ Students that ❤️ Save My Exams

the (exam) results speak for themselves:

  • I would just like to say a massive thank you for putting together such a brilliant, easy to use website.I really think using this site helped me secure my top gradesin science and maths. You really did save my exams! Thank you.

    Beth
    IGCSE Student

  • This website is soooo useful and I can’t ever thank you enough for organising questions by topic like this. Furthermore, the name of the website could not have been more appropriate as it literally did SAVE MY EXAMS!

    Fathima
    A Level Student
Test yourself

Did this page help you?

Previous:Graphs of Reciprocal Trigonometric FunctionsNext:Compound Angle Formulae
Roger B

Author: Roger B

Expertise: Maths Content Creator

Roger's teaching experience stretches all the way back to 1992, and in that time he has taught students at all levels between Year 7 and university undergraduate. Having conducted and published postgraduate research into the mathematical theory behind quantum computing, he is more than confident in dealing with mathematics at any level the exam boards might throw at you.

Download notes on Identities with Reciprocal Trigonometric Functions