Réitigh f(x)=x^2+tanx-operatorname{ctg}x

$$f ( x ) = x ^ { 2 } + \tan x - \operatorname { ctg } x$$

Réitigh do f. (complex solution)

$$\left\{\begin{matrix}f=\frac{i\left(-ix^{2}\sin(2x)+2i\cos(2x)\right)}{x\sin(2x)}\text{, }&\nexists n_{1}\in \mathrm{Z}\text{ : }x=\frac{\pi n_{1}}{2}\\f\in \mathrm{C}\text{, }&2\left(-ix^{2}\sin(2x)+2i\cos(2x)\right)=0\text{ and }\exists n_{2}\in \mathrm{Z}\text{ : }x=-\frac{\pi n_{2}}{2}\text{ and }\nexists n_{1}\in \mathrm{Z}\text{ : }x=\frac{\pi n_{1}}{2}\end{matrix}\right.$$

Céimeanna chun Cothromóidí Líneacha a Réiteach

Tá an chothromóid i bhfoirm chaighdeánach.

$$xf=\tan(x)-\cot(x)+x^{2}$$

Roinn an dá thaobh faoi x.

$$\frac{xf}{x}=\frac{\frac{\frac{1}{\cos(x)}-2\cos(x)}{\sin(x)}+x^{2}}{x}$$

Má roinntear é faoi x cuirtear an iolrúchán faoi x ar ceal.

$$f=\frac{\frac{\frac{1}{\cos(x)}-2\cos(x)}{\sin(x)}+x^{2}}{x}$$

Roinn x^{2}+\frac{\frac{1}{\cos(x)}-2\cos(x)}{\sin(x)} faoi x.

$$f=\frac{\frac{1}{\cos(x)}-2\cos(x)}{x\sin(x)}+x$$

Réitigh do f.

$$f=\frac{x^{2}\sin(2x)-2\cos(2x)}{x\sin(2x)}$$

$$\nexists n_{1}\in \mathrm{Z}\text{ : }x=\frac{\pi n_{1}}{2}$$

Céimeanna chun Cothromóidí Líneacha a Réiteach

Tá an chothromóid i bhfoirm chaighdeánach.

$$xf=\tan(x)-\cot(x)+x^{2}$$

Roinn an dá thaobh faoi x.

$$\frac{xf}{x}=\frac{-2\cot(2x)+x^{2}}{x}$$

Má roinntear é faoi x cuirtear an iolrúchán faoi x ar ceal.

$$f=\frac{-2\cot(2x)+x^{2}}{x}$$

Roinn x^{2}-2\cot(2x) faoi x.

$$f=-\frac{2\cot(2x)}{x}+x$$