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# Quick question (C3 Trigonometry) watch

1. If you have cos2A = sin2A and you divide both sides by cos2A, why are you then left with tan2A = 1 and not tan2A = 0 ??

This is probably a really dumb question but I'm trying to actually understand the maths rather than just accept the answers on the mark scheme and memorise the method.

2. anything divided by itself is 1. 7/7=1 x/x=1 12345/12345=0. so cos2A/cos2A=1
3. 12345/12345 = 1 sorry
4. (Original post by Suprite)
anything divided by itself is 1. 7/7=1 x/x=1 12345/12345=1. so cos2A/cos2A=1
^this
5. (Original post by jessyjellytot14)
If you have cos2A = sin2A and you divide both sides by cos2A, why are you then left with tan2A = 1 and not tan2A = 0 ??

This is probably a really dumb question but I'm trying to actually understand the maths rather than just accept the answers on the mark scheme and memorise the method.

What happens when you divide something by itself? What do you get? It's not 0.

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