Смотри /////////////////////////////
sin2a=2sinacosa=-2*3*4/25=-24/25
sina=3/5 cosa=-4/5
tga/2=sina/(1-cosa)=sqrt(3)/2(1+1/2)=sqrt(3)/3
cosa=-1/2
((х^2-10х+25)/(х^2-25))^3:((х-5)/(х+5))^3=1
((х-5)^2 /(х-5)(х+5))^3:((х-5)/(х+5))^3=1
(х-5 / х+5 )^3 : (х-5 /х+5)^3 =1
(х-5 / х+5 )^0 =1
1=1
а^0=1
а^m :a^n =a^m-n у нас
а^3 :а^3=а^3-3 =а^0=1
15m²n - 5n²m = 5mn(3m - n)
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