Use implicit differentiation to find an equation of the tangent line to the curve

sin(x+y)=2x−2y at the point (π,π).
Tangent Line Equation:

1 answer

To find the equation of the tangent line to the curve sin(x+y) = 2x - 2y at the point (π, π), we first need to find the derivative of the curve with respect to x.

Implicit differentiation:
Differentiating both sides with respect to x using chain rule, we have:

cos(x+y)(1+dy/dx) = 2 - 2(dy/dx) ⟹ cos(x+y)(1+dy/dx) - 2 + 2(dy/dx) = 0

Now we need to solve for dy/dx:

(dy/dx)(2+cos(x+y)) = 2 - cos(x+y) ⟹ dy/dx = (2 - cos(x+y)) / (2 + cos(x+y))

Now we calculate dy/dx at the point (π, π):

dy/dx = (2 - cos(2π)) / (2 + cos(2π)) = (2 - 1) / (2+1) = 1/3.

Now we have the slope (dy/dx) of the tangent line at the point (π, π).
To find the equation of the tangent line, we use the point-slope form:

y - y1 = m(x - x1)

Where m = dy/dx, x1 = π and y1 = π. Plugging in the values, we get:

y - π = 1/3 (x - π)

Now, we can rewrite the equation of the tangent line to a more standard form:

y = (1/3)x - (1/3)π + π

So, the equation of the tangent line is:

y = (1/3)x + (2/3)π.