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# Trigonometric proof watch

Prove that 2sinxcosx/tanx = 2-2sin^2(x)
2. (Original post by gcsemusicsucks)
Hope it helps!
3. (Original post by Mr M)

It's considered poor form to work on both sides of an identity at the same time. Start on one side and work towards the other.
Sorry! And I don't think I worked on both sides at the same time? I worked from the LHS
4. (Original post by gcsemusicsucks)
Sorry! And I don't think I worked on both sides at the same time? I worked from the LHS
You didn't - it was my mistake, my head doesn't rotate 90 degrees very easily.
5. (Original post by gcsemusicsucks)
Sorry! And I don't think I worked on both sides at the same time? I worked from the LHS
Could you edit and remove your solution and just give a hint
Prove that 2sinxcosx/tanx = 2-2sin^2(x)
Division by tan is the same as multiplication by cot. Also consider using Pythagoras' identity.
Prove that 2sinxcosx/tanx = 2-2sin^2(x)
Could you perhaps use any trigonometric identities to help you move in the right direction?
8. (Original post by Desmos)
Division by tan is the same as multiplication by cot. Also consider using Pythagoras' identity.
I think talking about cot would be overcomplicating things. But yes Pythagoras' identity would be useful.

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