Simplify the trigonometric expression $\frac{\frac{\frac{1-\cos\left(a\right)}{\sin\left(a\right)}}{\sin\left(a\right)}}{1-\cos\left(a\right)}$

$factor\left(121+198x^6+81x^{12}\right)$

$\tan\left(30+120\right)$

$factor\left(27x^3+135x^2+225x+125\right)$

$factor\left(x^2-2x+1\right)$

$factor\left(x^3-3x^2-4x+12\right)$

$\frac{7\sin\left(62\right)}{\sin\left(62\right)}$

$\sec\left(2+\csc\left(2\right)\right)$