It is given that x and y are parametrically connected by the equations,
x=a( cosθ+θsinθ )(1)
And,
y=a( sinθ−θcosθ )(2)
Differentiate equation (2) with respect to θ.
dy dθ =a d( cosθ+θsinθ ) dθ dy dθ =a( cosθ−cosθ+θsinθ ) dy dθ =a( θsinθ ) dy dθ =aθsinθ
Differentiate equation (1) with respect to θ.
dx dθ =a d( cosθ+θsinθ ) dθ dx dθ =a( −sinθ+sinθ+θcosθ ) dx dθ =a( θcosθ )
We know that,
dy dx = dy dθ dx dθ
Substitute the value of dy dθ and dx dθ .
dy dx = a( θsinθ ) a( θcosθ ) dy dx = sinθ cosθ dy dx =tanθ
Thus, the solution is dy dx =tanθ.
x=sinθ+θcosθ,y=cosθ−θsinθ,then(dydx)θ=π2