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maths a level question

9LIZZYS

Express 2cos θ – sin θ in the form Rcos(θ + α)

find R and α

???

Reply 1

MindMax2000

Universities Forum Helper

Original post by 9LIZZYS

Express 2cos θ – sin θ in the form Rcos(θ + α)

find R and α

???

Since you only need to express the equation in the form and not derive the form (assuming this is a 2-3 mark question), you can just apply the identities.
See the following: https://www.examsolutions.net/tutorials/harmonic-identities/

As we cannot provide you with the exact solutions to your question as per TSR's policies, we can only provide you hints like those above.

For your exams, you would want to memorise the harmonic identities.