Дано
$$frac{cos{left (- a + frac{3 pi}{2} right )} + cos{left (a + pi right )}}{sin{left (a – frac{pi}{2} right )} 2 cos{left (- a right )} + 1}$$
Подстановка условия
$$frac{cos{left (- a + frac{3 pi}{2} right )} + cos{left (a + pi right )}}{sin{left (a – frac{pi}{2} right )} 2 cos{left (- a right )} + 1}$$
(cos((3*pi)/2 – (3/2)) + cos(pi + (3/2)))/(1 + (2*cos(-(3/2)))*sin((3/2) – pi/2))
$$frac{cos{left (- (3/2) + frac{3 pi}{2} right )} + cos{left ((3/2) + pi right )}}{sin{left ((3/2) – frac{pi}{2} right )} 2 cos{left (- (3/2) right )} + 1}$$
(cos((3*pi)/2 – 3/2) + cos(pi + 3/2))/(1 + (2*cos(-3/2))*sin(3/2 – pi/2))
$$frac{cos{left (- frac{3}{2} + frac{3 pi}{2} right )} + cos{left (frac{3}{2} + pi right )}}{sin{left (- frac{pi}{2} + frac{3}{2} right )} 2 cos{left (- frac{3}{2} right )} + 1}$$
(-cos(3/2) – sin(3/2))/(1 – 2*cos(3/2)^2)
$$frac{- sin{left (frac{3}{2} right )} – cos{left (frac{3}{2} right )}}{- 2 cos^{2}{left (frac{3}{2} right )} + 1}$$
Степени
$$frac{- sin{left (a right )} – cos{left (a right )}}{- 2 cos^{2}{left (a right )} + 1}$$
Численный ответ
(cos(pi + a) + cos((3*pi)/2 – a))/(1.0 + 2.0*cos(-a)*sin(a – pi/2))
Рациональный знаменатель
$$frac{- sin{left (a right )} – cos{left (a right )}}{- 2 cos{left (- a right )} cos{left (a right )} + 1}$$
Объединение рациональных выражений
$$frac{- cos{left (a right )} + cos{left (frac{1}{2} left(- 2 a + 3 piright) right )}}{2 sin{left (frac{1}{2} left(2 a – piright) right )} cos{left (a right )} + 1}$$
Общее упрощение
___ / pi
/ 2 *sin|a + –|
4 /
—————–
cos(2*a)
$$frac{sqrt{2} sin{left (a + frac{pi}{4} right )}}{cos{left (2 a right )}}$$
Соберем выражение
$$frac{sin{left (a right )}}{cos{left (2 a right )}} + frac{cos{left (a right )}}{cos{left (2 a right )}}$$
Общий знаменатель
-(-sin(a) + cos(pi + a))
————————-
-1 + 2*cos(a)*cos(-a)
$$- frac{- sin{left (a right )} + cos{left (a + pi right )}}{2 cos{left (- a right )} cos{left (a right )} – 1}$$
Тригонометрическая часть
___ / pi
/ 2 *sin|a + –|
4 /
—————–
cos(2*a)
$$frac{sqrt{2} sin{left (a + frac{pi}{4} right )}}{cos{left (2 a right )}}$$
Комбинаторика
cos(a) + sin(a)
—————
2
-1 + 2*cos (a)
$$frac{sin{left (a right )} + cos{left (a right )}}{2 cos^{2}{left (a right )} – 1}$$