$\int\frac{1}{2}sen\left(\frac{1}{3}x+3\right)\cdot cos\left(-\frac{1}{2}x\right)dx$

$\frac{1}{2}\int\left(\frac{x}{x^2+x+1}\right)dx$

$\left(-4\right)^2+2\left(-4\right)-1$

$27\cdot20$

$cos\left(x+y\right)cos\left(y\right)+\:sin\left(x+y\right)sin\left(y\right)=cosx$

$\int2xn^{4x}\sin\left(5x\right)dx$

$\int\frac{2x}{2x-1\left(x^2+25\right)}dx$