<s>[INST] Area bounded by $y=\sqrt{\frac{1+\sin{x}}{\cos{x}}}$ and $y=\sqrt{\frac{1-\sin{x}}{\cos{x}}}$ 
The area of the region between the curves
  $y=\sqrt{\frac{1+\sin{x}}{\cos{x}}}$ and
  $y=\sqrt{\frac{1-\sin{x}}{\cos{x}}}$ bounded by the lines $x=0$ and
  $x=\frac{\pi}{4}$ is:
a) $\int_{0}^{\sqrt{2}-1}\frac{t}{(1+t^2)\sqrt{1-t^2}}dt$
b) $\int_{0}^{\sqrt{2}-1}\frac{4t}{(1+t^2)\sqrt{1-t^2}}dt$
c) $\int_{0}^{\sqrt{2}+1}\frac{4t}{(1+t^2)\sqrt{1-t^2}}dt$
d) $\int_{0}^{\sqrt{2}+1}\frac{t}{(1+t^2)\sqrt{1-t^2}}dt$

My Attempt:
So I started with,
$$\int_{0}^{\frac{\pi}{4}}\sqrt{\frac{1+\sin{x}}{\cos{x}}}-\sqrt{\frac{1-\sin{x}}{\cos{x}}}dx$$
$$\int_{0}^{\frac{\pi}{4}}\frac{2\sin{x}}{\sqrt{\cos{x}}(\sqrt{1+\sin{x}}+\sqrt{1-\sin{x}})}dx$$
Putting $\cos{x}=u$
$$\int_{1}^{\frac{1}{\sqrt{2}}}\frac{-2}{\sqrt{u}(\sqrt{1+\sqrt{1-u^2}}+\sqrt{1-\sqrt{1-u^2}})}du$$
Putting $u=\frac{1}{w}$ and further $w-1=t$,
I end up with,
$$\int_{0}^{\sqrt{2}-1}\frac{2}{(1+t)(\sqrt{(1+t)+\sqrt{(1+t)^2-1}})+(\sqrt{(1+t)-\sqrt{(1+t)^2-1}})}dt$$
But I am not able to reduce this to any of the given options? Am I miscalculating something or this is reducible?
Any hints would be helpful. 
Thank you.
 [/INST] HINT
We could use Tangent half-angle substitution to obtain
$$\sin x=\frac{2t}{1+t^2}\quad \cos x=\frac{1-t^2}{1+t^2}\quad t=\tan \frac x 2 \implies dt=\frac12(1+t^2)dx$$
then
$$\int_{0}^{\frac{\pi}{4}}\sqrt{\frac{1+\sin{x}}{\cos{x}}}-\sqrt{\frac{1-\sin{x}}{\cos{x}}}dx=\int_0^{\sqrt2 -1} \left(\sqrt{\frac{(1+t)^2}{1-t^2}}-\sqrt{\frac{(1-t)^2}{1-t^2}}\right)\frac2{1+t^2}dt=\ldots$$
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