Answer
$y=2x-2$
Work Step by Step
The equation of the tangent line at $(1,0)$ is:
$$y=0+f'(1)(x-1)$$
Using the chain rule it follows:
$$f'(x)=\frac{2}{x}\cos(2\ln(x))$$
$$f'(1)=\frac{2}{1}\cos(2\ln(1))$$
$$f'(1)=2$$
so:
$$y=0+2(x-1)$$
$$y=2x-2$$