$\lim_{x\to-\infty}\left(x^{2}-2x+1\right)$

$\frac{1}{sec^2k}\:cos^2k\:+cos^4k$

$6\left(2\right)\left(-3\right)+8\left(2\right)$

$\lim_{x\to1}\frac{\sqrt{x^2+500x-1}-\sqrt{x^3+500x-1}}{x-1}$

$\frac{x^5-x^4+x^2-2}{x^2+1}00$

$140\:-\:\left(-370\right)$

$\left(1-tan\left(x\right)\right)\cdot\left(sen\left(2x\right)+1\right)$