Eric Nicholas K's answer to Angeline Wong's Secondary 3 A Maths Singapore question.

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Eric Nicholas K
Eric Nicholas K's answer
5997 answers (Tutor Details)
1st
Here. A tricky one.
Eric Nicholas K
Eric Nicholas K
4 years ago
I went in the wrong step by using double angle formula the first time. If you used that the first time, then you can try my current method.