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3-4cos^2t=0

2sin^2+sint-1=0

cos (pi/2-t) - sin (pi+t) = ^2

1) 3-4cos²t=0

-4cos²t=-3

4cos²t=3

cos²t=3/4

cost=√3/2

t=π/6+2πk, k∈Z

2) 2sin²t+sint-1=0

пусть sintt=0, IxI≤1, тогда

2x²+x-1=0

Д=1-4*2 * (-1) = 1+8=9 (3)

x1=-1+3/4=2/4=1/2

x2=-1-3/4=-1

1) sint=1/2

t = (-1) ^k * π/6+πk, k∈Z

2) sint=-1

t = (-1) ^k+1 * π/2, k∈Z

3) cos (π/2-t) - sin (π+t) = √2

sint+sint=√2

2sint=√2

sint=√2/2

t = (-1) ^k * π/4+πk, k∈Z