PART 12：積化和差 例題2

不定積分 \(\int {\sin 6x\cos 4x} dx = ?\)

SOL:

\(\int {\sin 6x\cos 4x} dx = \frac{1}{2}\int {\left( {\sin 10x + \sin 2x} \right)} \;dx\)

\( = \frac{1}{2}\left( { - \frac{1}{{10}}\cos 10x - \frac{1}{2}\sin 2x} \right) + C\)