第4章 4.3

(1)

5−x2\sqrt{5-x^2}

∫5−x2 dx=12{x5−x2+5sin⁡−1x5}+C\int \sqrt{5-x^2}\,dx = \frac{1}{2}\left\{x\sqrt{5-x^2} + 5\sin^{-1}\frac{x}{\sqrt{5}}\right\} + C (C は積分定数)

(2)

x2+3\sqrt{x^2+3}

∫x2+3 dx=12{xx2+3+3log⁡∣x+x2+3∣}+C\int \sqrt{x^2+3}\,dx = \frac{1}{2}\left\{x\sqrt{x^2+3} + 3\log\left|x+\sqrt{x^2+3}\right|\right\} + C (C は積分定数)

(3)

4x−x2\sqrt{4x-x^2}

∫4x−x2 dx=∫4−(x−2)2 dx=12{(x−2)4−(x−2)2+4sin⁡−1x−22}+C\int \sqrt{4x-x^2}\,dx = \int \sqrt{4-(x-2)^2}\,dx = \frac{1}{2}\left\{(x-2)\sqrt{4-(x-2)^2} + 4\sin^{-1}\frac{x-2}{2}\right\} + C

=12{(x−2)4x−x2+4sin⁡−1x−22}+C= \frac{1}{2}\left\{(x-2)\sqrt{4x-x^2} + 4\sin^{-1}\frac{x-2}{2}\right\} + C

(C は積分定数)

解説: r31bn1z