Riješi ∫ (from 4 to 15) of f(x) wrt x-int_4^8f(x)dx=int_a^bf(x)dx

$$\int _ { 4 } ^ { 15 } f ( x ) d x - \int _ { 4 } ^ { 8 } f ( x ) d x = \int _ { a } ^ { b } f ( x ) d x$$

Riješite za a

$$\left\{\begin{matrix}a=\sqrt{b^{2}-161}\text{; }a=-\sqrt{b^{2}-161}\text{, }&f\neq 0\text{ and }|b|\geq \sqrt{161}\\a\in \mathrm{R}\text{, }&f=0\end{matrix}\right,$$

Riješite za b

$$\left\{\begin{matrix}b=\sqrt{a^{2}+161}\text{; }b=-\sqrt{a^{2}+161}\text{, }&f\neq 0\\b\in \mathrm{R}\text{, }&f=0\end{matrix}\right,$$