implciitely differentiate x^2+y^2=L^2
is it 2xdx/dx +2ydy/dt=0
becase L is a function of nothing??

Question

implciitely differentiate x^2+y^2=L^2
is it 2xdx/dx +2ydy/dt=0
becase L is a function of nothing??

anonymous · Answer

What are you differentiating with respect to? x? And what does L represent here? Is it a constant?

anonymous · Answer

well L is a fixed given L=25ft
where as x fixes is given at x=7, y=sqroot 25^2-7^2=24
x and y are both changing with respect to t (its a related rates problem)
25ft represent the size "a 25 ft ladder"

anonymous · Answer

Okay that sounds right then. So you get 2x+2yy'=0, y'=-x/y

anonymous · Answer

The Total Derivative of x^2+y^2=L^2 is:$$2 x dx+2 y dy=2 L dL $$if L is a constant, then dL is zero and the RHS is zero.$$2 x dx+2 y dy=0 $$

anonymous · Answer

ty