<span>б)36+95-205*48/164=36+95-60=71</span>
cos60*cos(35+25)=cos^2(60)=1/4
А)D(y)∈(-∞;∞)
b)D(y)∈(-∞;∞)
v)D(y)∈(-∞;0) U (0;∞)
g)D(y)∈[-3;∞)
Ответ a,b
(5b^2-10)(5b^2+10)=25b^4-100=25(b^4-4)=25(b^2-2)(b^2+2)
Cos(pi/2+x) = -sinx
cos2x= cos^2x - sin^2x
-sinx = cos^2x - sin^2x
cos^2x =1 - sin^2x
-sinx = 1-sin^2x - sin^2x
2sin^2x - sinx - 1 =0
sinx = t
2t^2-t-1=0
D = 1 + 8 = 9
t1 = 1+3/4 = 4/4 = 1
t2 = -2/4 = -0.5
sinx = 1
x = pi/2+2pin
sinx = -0.5
x = -pi/6+2pin
x = -5pi/6+2pin