У^2-5у+6у-30-14у^2-21у
подобные слагаемые
-14у^2 и у^2
-5у и 6у и -21у
-30
(tg²α-sin²α)/(cos²α-ctg²α)=(sin²α/cos²α-sin²α)/(cos²α-cos²α/sin²α)=
=((sin²α*-sin²α*cos²α)/cos²α)/((sin²α*cos²α-cos²α)/sin²α)=
=(sin²α*(1-cos²α))/cos²α)/(cos²α*(sin²α-1))/sin²α)=(sin⁴α/cos²α)/(cos⁴α/sin²α)=
=sin⁶α/cos⁶α=tg⁶α.
1) y=cos^2(x/2)-sin^2(x/2)=cos(2*x/2)=cosx F(X)=sinx +C
2) y=1-2sin^2(x/2)=cos(2*x/2)=cosx F(x)=sinx +C
|6x-5/2|≤5
6x-5/2≤5 |×2
6x-5≤10
6x≤15 |÷6
x≤2,5
х∈(-∞;2,5)