Помогите!!!!! тригонометрия. Created by masyanya1997. algebra-ru

Помогите!!!!! тригонометрия...

masyanya1997 @masyanya1997

July 2022 1 8 Report

Помогите!!!!!
тригонометрия

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sedinalana

Verified answer

93
cos^4a-sin^4a=(cos²a-sin²a)(cos²a+sin²a)=cos2a*1=cos2a=1-2sin²a
1-2sin²a=1-2sin²a
94
ctga-tga=cosa/sina-sina/cosa=(cos²a-sin²a)/(sinacosa)=cos2a/(sinacosa)=
=(1-2sin²a)/(sinacosa)
(1-2sin²a)/(sinacosa)=(1-2sin²a)/(sinacosa)
95
tga/sina-sina/ctga=sina/cosa:sina-sina:cosa/sina=1/cosa-sin²a/cosa=
=(1-sin²a)/cosa=cos²a/cosa=cosa
cosa=cosa
96
(tg²a+1)/(tg²a-1)=(sin²a/cos²a+1):(sin²a/cos²a-1)=
(sin²a+cos²a)/cos²a:(sin²a-cos²a)/cos²a=1/cos²a*cos²a/(sin²a-cos²a)=
=1/(sin²a-cos²a)
1/(sin²a-cos²a)=1/(sin²a-cos²a)
97
=(-sina-sina)²+(cosa+cosa)²=4sin²a+4cos²a=4(sin²a+cos²a)=4
98
=(ctga+ttga)²-(ctga+tga)²=0
99
=ctga*(-sina)/cosa+sina*sina-cosa*(-cosa)=ctga*(-tga)+sin²a+cos²a=
=-1+1=0
0=0
100
=(cos²a+cos²a-cosa*cosa)/ctg²a*tg²a=(cos²a+cos²a-cos²a)/1=cos²a
cos²a=cos²a
101
(-cos³a*cosa)/(-ctg³a*sin³a)=ctg³a*cosa/ctg³a=cosa
cosa=cosa
102
=(2cos2acosa+2cos2a)/(2sin2acosa+2sin2a)=2cos2a(cosa+1)/2sin2a(cosa+1)=ctg2a
103
=(2sinacos3a+2cos3a)/(-2sin3asina-2sin3a)=2cos3a(sina+1)/[-2sin3a(sina+1)]=-ctg3a

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