1)sin²a+cos²a+tg²a=1+tg²a=1/cos²a
2)tga*ctga+1=1+1=2
3)(sina+sina/cosa):(1+cosa)=(sinacosa+sina)/cosa:(1+cosa)=
=sina(cosa+1))/(cosa(1+cosa)=sina/cosa=tga
Tg2a=2tga/(1-tg²a) ⇒tga/(1-tg²a)=0.5tg2a
tg π/8 /(1- tg² π/8)=0.5tg(2*π/8)=0.5tg π/4=0.5
отв:0,5
И) =n2(81-n2)=n2(9-n)(9+n)
к) =z3(4-100z2)=z3(2-10z)(2+10z)
л) =m(x2-49)=m(x-7)(x+7)
м) =a(b2-4c2)=a(b-2c)(b+2c)
н) =b(9b2-1)=b(3b-1)(3b+1)
о) =c(c2-b2)=c(c-b)(c+b)
п) =(p2-4)(p2+4)=(p-2)(p+2)(p2+4)
р) =(x2-9)(x2+9)=(х-3)(х+3)(х2+9)
с)
т)