$\left(a-c\right)^2;\:a=-1;\:c=-\frac{1}{2}$

$\frac{\left(2-cot\left(x\right)\right)}{2sec\left(x\right)-csc\left(x\right)}$

$3+2\sin\left(x\right)=-\sin\left(x\right)+4$

$\frac{d}{dx}\sqrt{2x^2-23}\:$

$27\cdot\frac{2\pi}{3}$

$\lim_{x\to\infty}\left(\frac{x\:+\:a}{x\:+\:b}\right)^{cx}$

$\frac{x^4-x}{3x^2}$