$$f\left(x\right)=5x^4-\sin^3x$$

$$f\left(x\right)=x^2+x\sin^3x$$

$$f\left(x\right)=2+x\cos^4x$$

$$f\left(x\right)=\frac{\sin^3x}{\sin x^2}$$

$$f\left(x\right)=-\cos^3x$$

$$f\left(x\right)=x^3+\frac{\cos^3x}{tg^2x}$$

$$f\left(x\right)=2x+\frac{\cos^3x}{tg^3x}$$

$$f\left(x\right)=\frac{2\sin^3x}{\operatorname{ctg}x^3}$$

$$\frac{2}{5}\pi$$

$$2,5\pi$$

$$4\pi$$

$$5\pi$$

$$\left[3;7\right)$$

$$\left[3;5\right]$$

$$\left(3;7\right]$$

$$\left(2;7\right]$$