$\int\left(\frac{\:\sec\:\:^4\left(\ln\:\:\left(x\right)+3\right)}{\:x}\right)dx$

$x+4y-z+3w=10\:$

$\frac{du}{dx}=-x-u$

$\sin\left(x\right).\cot\left(x\right)+\cos\left(x\right)=\cot\left(x\right)\cos\left(x\right)$

$\left(+9.290\right)\:-\:\left(+9.876\right)$

$17\cdot125$

$\left(1-cos^2\left(x\right)\right)\left(1-cos^2\left(x\right)\right)\left(1-cos^2\left(x\right)\right)$