$6\left(9x^5-15x^3+6x\right)^2$

$2.5\left(4.2+7.4y\right)-3.6\left(8x-4.5y\right)-\left(2.4x+6y\right)$

$\int\frac{e^{4x}}{\sqrt{e^{2x}-16}}dx$

$\int\frac{x}{\sqrt{9x^2+25}}dx$

$\int_0^{\pi}\left(x+x^2\right)\cdot\sin\left(x\right)dx$

$36x^6+36x^5+9^4$

$\cot\left(\frac{\pi}{2}-a\right)$