Задача 51192 ...

sova

2020-05-22 10:46:04

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sin( α -(3π/2))=-sin((3π/2)- α )

По формулам приведения
sin((3π/2)- α )=-cos α ⇒

[b]sin( α -(3π/2))=cos α [/b]



tg((π/2)- α )=ctg α


cos((π/2)- α )=sin α


sin(π+ α )=-sin α

sin^2(π+ α )=(-sin α)^2=sin^2 α