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# Need C3 Heelp watch

1. Given that x = 4 sin (2y + 6), find dy/dx in terms of x.

my answer to the Q was dy/dx= 1/8cos(2y+6)
but i didnt know how to write it in term of x can someone help me plz
2. You have x = 4 sin(2y+6)
Divide by 4 both sides then inverse it to get arcsin(x/4) then substitute it into 2y+6
3. 1. Work out dx/dy.
2. Use the fact that dy/dx = 1/(dx/dy)
3. Express it in terms of x by using the identity (sin z)^2 + (cos z)^2 = 1 for all z.
4. thanx
5. I did this paper the other day.
Superman Jr is right.

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Updated: January 17, 2010
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