$6cos^23x-7cos3x-3=0$

$\lim_{x\to0}\left(\frac{\tan\left(e^x+1\right)-e^x+1}{\left(e^x-1\right)^3}\right)$

$\int\frac{\sqrt{x}+1}{\sqrt{x}}dx$

$\frac{cos\left(\pi+x\right)}{\cos\left(\frac{3\pi}{2}-x\right)}$

$\frac{dy}{dx}\left(x^3+3y^4=2xy\right)$

$3x+2<2x+4$

$i^2+18i+49$