$\frac{\sin\left(2.a\right).\cos\left(a\right)-\sin\left(a\right).\cos\left(2.a\right)}{\sin\left(a\right).\cos\left(a\right)}$

$\int\frac{\left(12x^2+8\right)}{\left(2x^3+4x-5\right)}dx$

$x\left(3x^2-9\right)$

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

$\frac{cos^2\left(x\right)-sin^2\left(x\right)}{sin\left(x\right)}+sin\left(x\right)=\frac{cot\left(x\right)}{sec\left(x\right)}$

$2x^2-8x-13=7$

$\int_{-6}^6\left(\sqrt{36-x^2}\right)dx$