$sin^2\left(x\right)\:\frac{sin\left(x\right)cos\left(x\right)}{tan\left(x\right)}$

$21\cdot15$

$\int\frac{\left(x^2\right)}{\sqrt{-9x^2+16}}dx$

$\int_{0\:}^{\pi\:}\left(\frac{6}{\pi\:}x-3\right)\left(\cos\left(nx\right)\right)dx$

$12ab+3b+4b+1$

$x=1,\:y=2,\:c=3,\:m=2,\:n=0\:$

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