Выражение: (cos(5π/2-α)- sin(α-π/(π-α)+cos(3π-α)) при значении α=-π/8

(cos(5π/2-α)- sin(α-π/(π-α)+cos(3π-α))=(cos(2π+π/2-α)+sin(π/2-α(π-α)+cos(2π+π-α))=(cos(π/2-α)+sin(π/2-α(π-α)+cos(π-α))=(sinα+cosα)(sinα-cosα)=sin²α-cos²α=-(cos²-sin²α)=-cos2α=-cos(-π/8×2)=-cos(π/4)=-√2/2

X^3 + 5x^2 - 36x - 180=0 x^2(х + 5) - 36(x +5)= (x^2 - 36)(x +5)=(х-6)(х+6)(х+5)=0 ответы: х=6 х=-6 х=-5

p(a)=m/n

 

m=7900

n=40000

p(a)=m/n=7900/40000=79/400=0,1975