Write the equation of the tangent drawn to the curve

Given that $y=\sin x$

The slope of the tangent:

$\frac{d y}{d x}=\cos x$

For origin $(a, b)$ slope $=\cos 0=1$

Equation of the tangent:

$\left(y-y_{1}\right)=$ Slope of tangent $\times\left(x-x_{1}\right)$

So, the equation of the tangent at the point $(0,0)$

$y-0=1(x-0)$

$\Rightarrow y=x$