Why does (sin 2x) / (cos 2x) = tan 2x . I thought the answer was tan x because the 2s cancel each other out
C2 maths help Watch
- Thread Starter
- 19-05-2017 14:33
- TSR Support Team
- Study Helper
- 19-05-2017 14:38
You can only cancel a number/variable from the top and bottom of a fraction if this number is a factor of the whole numerator and the whole denominator.
2 is not a factor of so you can't cancel it but 2 would be a factor of for example.
- Very Important Poster
- 19-05-2017 14:39
Then we have siny/cosy = tany.
There is no cancelling out, which is a common misconception at a first glance.
Please make your thread titles clearer, specifying C2 is very useful and better than a large number of threads but 'C2 trig question' would be better still