Edexcel A-level Maths Chapter 7 Trigno

Hello,

For question 2a and 2b, I found the maximum values by calculating R. However, please can you explain how to find the x values.

Many thanks in advance

(edited 5 months ago)

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Reply 1

mqb2766

What values of # in cos(#) correspond to the output being 1? Then just reason about the value of x.

Reply 2

taqiyah

Original post by mqb2766

What values of # in cos(#) correspond to the output being 1? Then just reason about the value of x.

Which equation with cos(#) are you referring to?

Reply 3

mqb2766

Original post by taqiyah

Which equation with cos(#) are you referring to?

One of the main reasons for transforming sin+cos to Rcos or Rsin is because its "easy" to analyse the min/max of Rcos or Rsin as it just corresponds to the points where cos or sin is min/max. So I / you must be referring to the harmonic form.

Note in your working you miss out = signs and youve not wrote the harmonic expression clearly at the end. Both are worth doing.