Question

упростите
sina/2cos^2 a/2​

Answer 1

$\displaystyle\bf\\\frac{Sin\alpha }{2Cos^{2} \frac{\alpha }{2} } =\frac{2Sin\frac{\alpha }{2} Cos\frac{\alpha }{2} }{2Cos^{2} \frac{\alpha }{2} } =\frac{Sin\frac{\alpha }{2} }{Cos\frac{\alpha }{2} } =tg\frac{\alpha }{2}$