Find: sin(arccos(3/5))

Find the exact value of csc105 degrees

Simplify: sin (x+y) - sin(x-y)

Prove that: sin2x/cotx = 1-cos2x

Find the exact value of sin(x+ pi/3)

I know thats a lot but any help would be amazing!!! I'm awful at this!!

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- May 6th 2008, 12:08 PMantz215trignometric simplify
Find: sin(arccos(3/5))

Find the exact value of csc105 degrees

Simplify: sin (x+y) - sin(x-y)

Prove that: sin2x/cotx = 1-cos2x

Find the exact value of sin(x+ pi/3)

I know thats a lot but any help would be amazing!!! I'm awful at this!! - May 6th 2008, 01:09 PMantz215
btw how do you make the pi symbol on here??j

- May 6th 2008, 01:16 PMMoo
Hello,

$\displaystyle \sin(\arccos(3/5))=\pm \sqrt{1-(3/5)^2}$ (see where arccos 3/5 lies and conclude about the sign of the sine)

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Find the exact value of csc105 degrees

Quote:

Simplify: sin (x+y) - sin(x-y)

$\displaystyle \sin(x-y)=\sin(x)\cos(-y)+\cos(x)\sin(-y)$

Quote:

Prove that: sin2x/cotx = 1-cos2x

$\displaystyle \sin 2x=2 \cos x \sin x$

$\displaystyle \Longrightarrow \frac{\sin 2x}{cot x}=2 \sin^2(x)=\dots$

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Find the exact value of sin(x+ pi/3)

Quote:

btw how do you make the pi symbol on here??j

- May 6th 2008, 01:28 PMantz215
thank you! most of that made sense to me, but what didnt wasnt your fault!

- May 6th 2008, 01:31 PMMoo