|/(42c^5)=c|/(42c)
|/(-50c^5)=5c^2|/(-2c)
|/(8/c^4)=2/c * |/2
<span>(x-2)</span>²<span>>x(x-4)
x</span>²-4x+4>x²-4x
4>0
x∈R
Sбок = 2piRH=pi*D*H -> H=Sбок/piD=40pi/pi/5=8
<span>y' = tg' x + ctg' x = 1/(cos^2 (x) ) + (- 1/(sin^2 (x) ) = 1/(cos^2 (x) ) - 1/(sin^2 (x) ) = 1/(sin^2 (x) * cos^2 (x) ) = [(1-cos(2x))/2 ]*[(1+cos(2x))/2] = (1-cos^2 (2x) )/4</span>