Find the equation of the tangent and the normal to the following curves at the indicated points:
$x=\theta+\sin \theta, y=1+\cos \theta$ at $\theta=\pi / 2$
finding slope of the tangent by differentiating $x$ and $y$ with respect to theta
$\frac{\mathrm{dx}}{\mathrm{d} \theta}=1+\cos \theta$
$\frac{d y}{d \theta}=-\sin \theta$
Dividing both the above equations
$\frac{\mathrm{dy}}{\mathrm{dx}}=-\frac{\sin \theta}{1+\cos \theta}$
$\mathrm{m}$ (tangent) at theta $(\pi / 2)=-1$
normal is perpendicular to tangent so, $m_{1} m_{2}=-1$
$m$ (normal) at theta $(\pi / 2)=1$
equation of tangent is given by $y-y_{1}=m($ tangent $)\left(x-x_{1}\right)$
$y-1=-1\left(x-\frac{\pi}{2}-1\right)$
equation of normal is given by $y-y_{1}=m($ normal $)\left(x-x_{1}\right)$
$y-1=1\left(x-\frac{\pi}{2}-1\right)$