Представьте в виде произведения: сos \(\frac{\Pi}{5}\) + cos \(\frac{\Pi}{4}\) .
2 \(\cdot\) cos \(\frac{9\Pi }{40}\) \(\cdot\)
cos \(\frac{\Pi}{40}\)
2 \(\cdot\) cos \(\frac{\Pi}{20}\) \(\cdot\)
cos \(\frac{9\Pi }{20}\)