HELP! ASAP! MEDAL!
@dan815 @freckles @Nnesha @satellite73
@satellite73 @zepdrix
have you differentiated yet?
no. I'm stuck at that part.
we need product rule and chain rule mainly
would the left-hand side be sin2y + x(cos 2y)?
\[\frac{d}{dx}(x \sin(2y)) =\sin(2y)\frac{d}{dx}x+x \frac{d}{dx}\sin(2y) \\ \frac{d}{dx}(x \sin(2y))=\sin(2y)+x \cdot 2y'\cos(2y)\]
we need chain rule for the sin(2y) part
derivative of inside * outside
(sin(2y))' = (2y)'*cos(2y) = 2y'*cos(2y)
\[(x \sin(2y))'=(y \cos(2x))' \\ \sin(2y)+2y' x \cos(2y)=(y \cos(2x))'\]
the right hand side should be a bit easier now
I'm confused....How'd you get (y cos (2x))'?
I think you equation is x sin(2y)=y cos(2x) right?
Oh, right sorry. you put it together. I thought you were saying the derivative of the left side was that, lol
cool looking http://www.wolframalpha.com/input/?i=x*sin%282y%29%3Dy*cos%282x%29
Thanks. I have to go wat dinner. Hopefully I can figure out the rest myself. :/
eat*
k well put what you get for the right hand side and I will check it
when you get time
I got \(\Large\frac{dy}{dx} = \frac{-y\cos{2x}-\sin{2x}}{-\sin{2y}+\cos{2y}}\)
\[(x \sin(2y))'=(y \cos(2x))' \\ \sin(2y)+2y' x \cos(2y)=y' \cos(2x)-2 y \sin(2x) \\ y'(2 x \cos(2y)-\cos(2x))=-2y \sin(2x)-\sin(2y) \\ \] you dy.dx looks a little off
I changed it and ended up getting the equation y = 2x for my answer
(equation of line tangent to....)
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