1)arcsin 0 =0
2)arccos 1= 0 ;
3)arcsin√2/2 =π/4 ;
4)arccos 3 не существует угол косинус которой =3 ;
5)arcsin (-1) = -π/2 ;
6)arccos(-√3/2) = π -π/6 = 5π/6 ;
7)arctg 0 = 0 ;
8)arctg 1 =π/4 ;
9)arctg(-√3) = - π/3 ;
10)arcctg(-√3/3) = π -π/3= 2π/3 ;
11)arcsin(-1/2)+arccos 1 = -π/6 +0 = -π/6 ;
12) (arcsin -1)/2+ arccos 1 = -π/4+0= -π/4;
13)cos ( arccos 1) =1;
14)sin(arcsin√2/2) =√2/2 ;
15)arcsin (sin π/4) =arcsin(√2/2) =π/4 ;
16)arccos ( cos(-π/4))=arccos ( cos(π/4))=arccos (√2/2))=π/4 ;
17)cos (arcsin(-1/3))=cos(arccos(√8/3)= √8/3 =2√2/3 ;
18)tg(arccos(-1/4)) =tq(arctq(-√15) = - √15; 1+tq²α= 1/cos²α
19)sin(arcctg(-2)) =sin(arcsin(1/√5)=1/√5 ;
20) arcsin(cos π/9) =arcsin(sin(π/2 - π/9))=arcsin(sin7π/18) =7π/18 .
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Объяснение:
Объяснение:
1) 6x^2 + x - 1=0 6)5x^2 -7x +2=0
D=25 D=9
x1=1/3 x2=-1/2 x1=1 x2=2/5
2)2x^2 -9x +4=0 7)2x^2 +3x-5=0
D=49 D=49
x1=4 x2=0,5 x1=1 x2=2/5
3)-x^2+7x-10=0 8)3x^2 +8x-3=0
x^2 -7x+ 10=0 D=100
D=9 x1=1/3 x2=-3
x1=5 x2=2 9)2x^2- 7x+3=0
4)2x^2 - 5x+3=9 D=1
2x^2- 5x -6=0 x1=2 x2=1,5
D=73 10)3x^2+2x-5=0
x1= (5+√73)/2 D=64
x2=(5-√73)/2 x1=1 x2=-1 2/3
5)5x^2-3x-2=0
D=49
x1=1 x2=-2/5
x² + 6x + 8 = x² + 6x + 9 – 1 = (x + 3)² – 1 = (x + 3 + 1)(x + 3 – 1) = (x + 4)(x + 2)