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# C3 trig edexcel watch

1. hey im a bit stuck on this
im not 100% sure what to do

i need to
solve for values of theta from 0 to 360
theata = A to make it easier

sin2AcosA + sin^2A = 1

what do i do?
i multipled out to get
2sinAcosA . cosA + 0.5(1 - cos^A-1)

also can i get 2sinAcos^2A is that right?

am i goin right here
but i dont know where i need to go?

2. 2sin2AcosA + sin^2 A = 1

2sinAcos^2A = 1 - sin^2A

What can we do with the RHS ?

Heres a spoiler to what you have to do next

Spoiler:
Show
Take the RHS over to the left hand side and factorise. DO NOT DIVIDE you will lose a solution!!!
3. "2sinAcos^2A = 1 - sin^2A"
if i take it to the lhs i get
2sinAcos^2A - 1 + sin^2A = 0

how do i factorise this?

thx
4. What IS 1-sin^2A though?

I put the sin^2A over the RHS for a reason!
5. did u mean 1 - sinsquared A
or 1-sin to power of 2?

6. so it looks like now

can you finish it now?
7. yep - sorry didnt remem that identity i have cos^2 A as something else
thx man
8. np.

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