$\frac{d^2}{dx^2}\left(9x^3ln\left(7x\right)\right)$

$3\cdot41$

$\lim_{x\to0}\left(2sin\left(9x\right)ln\left(9x\right)\right)$

$x^2+y^2+2y+10=6$

$\frac{dy}{dx}\left(x^2y-y^2=6\right)$

$\lim_{x\to\frac{\pi}{2}}\left(2\cos\left(-3x\right)\sec\left(-9x\right)\right)$

$\int_{t\:}^{-1}\left(\frac{1}{\sqrt{2-w}}\right)dw$