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# Core 4 trigonometry watch

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1. Solve equation root2sin(theta+45) = 3costheta, 0<theta<360.

Okay where do I even start!!! I'm so STUCK, I tried the addition formula but I don't think I'm getting anywhere ...
2. (Original post by plower)
Solve equation root2sin(theta+45) = 3costheta, 0<theta<360.

Okay where do I even start!!! I'm so STUCK, I tried the addition formula but I don't think I'm getting anywhere ...

try using that on
3. (Original post by plower)
Solve equation root2sin(theta+45) = 3costheta, 0<theta<360.

Okay where do I even start!!! I'm so STUCK, I tried the addition formula but I don't think I'm getting anywhere ...
4. (Original post by DylanJ42)

try using that on

I did and then I got root2sinthetacos45 + root2costhetasin45 = 3costheta . So do I now divide by cos fit all of them?
5. (Original post by plower)
I did and then I got root2sinthetacos45 + root2costhetasin45 = 3costheta . So do I now divide by cos fit all of them?
If you evaluate all the constants then it should make things simpler i.e. what is cos(45), sin(45) ?

Then you should be able to simplify to just have a single sine term and a single cosine term and it will look like a C2 question.
6. here is a theta for you : Θ

and a square root: √

and a degree symbol: °

you cannot "divide by cos"....

√2sinΘcos45° + √2cosΘsin45° = 3cosΘ

instead join the two terms with cosΘ together... also put in fractions for cos45° and sin45°
7. (Original post by notnek)
If you evaluate all the constants then it should make things simpler i.e. what is cos(45), sin(45) ?

Then you should be able to simplify to just have a single sine term and a single cosine term and it will look like a C2 question.
(Original post by the bear)
here is a theta for you : Θ

and a square root: √

and a degree symbol: °

you cannot "divide by cos"....

√2sinΘcos45° + √2cosΘsin45° = 3cosΘ

instead join the two terms with cosΘ together... also put in fractions for cos45° and sin45°
(Original post by notnek)
Oooh GOT IT !! Thankyou so much guys for correcting me <3

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