I have two questions which I'm really stuck on and i was wondering if you could show me how to do them
Given x= cos(3y) find a) dx/dy in terms of y b)find dy/dx in terms of y ( i get thats one over part a but i got -sin(3y) which i don't think can be right)
c) hence find the equation of the normal to the curve x+cos(3y) at the point where y= π/6
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Last question is find the coordinates of the stationary points of the curve y= √2x+5 - x . the 2x+5 is all square rooted and the -x isn't. thanks in advance I really appreciate it!