<span>Ctg(11pi/2 + a) * sin(a + 7pi/2) * cos(3pi/2 - 2a) если cosa = 0,7
sin(a + 7pi\2) * cos(3pi\2 - 2a)= (sin(a + 7pi\2 - 3pi\2 + 2a) + sin (a + 7pi\2 + 3pi\2 - 2a))\2= (sin(3a + 4pi\2) +sin(10pi\2 - a))\2= (sin(3a+2pi)+sin(5pi-a))\2
ctg(11pi\2 + a)= cos</span>(11pi\2 + a)\sin(11pi\2 + a)
sin(3a+2pi)+sin(5pi-a)=2sin((3a+2pi+5pi-a)\2) * cos((3a+2pi-5pi+a)\2)= 2 sin((7pi+2a)\2) * cos((4a-3pi)\2)
cos(11pi\2 + a)\sin(11pi\2 + a)*(sin(3a+2pi)+sin(5pi-a))\2=cos(11pi\2 + a)\sin(11pi\2 + a) * sin((7pi+2a)\2) * cos((4a-3pi)\2)
101, 103, 105, 201, 203, 205, 301, 303, 305, 401, 403, 405, 501, 503, 505.
ответ : 15