`cos(x + y) = x` Find `dy/dx` by implicit differentiation.

Expert Answers
hkj1385 eNotes educator| Certified Educator

Note:- If y = cos(x) ; then dy/dx = -sin(x)

Now, 

`cos(x+y) = x`

`or, -sin(x+y)*{1 + (dy/dx)} = 1`

`or, 1+(dy/dx) = -1/sin(x+y)`

`or, 1+(dy/dx) = -cosec(x+y)`

`or, dy/dx = -1 - cosec(x+y)`

`or, dy/dx = -{1+cosec(x+y)}`