1) 2cos (-0.5x + π/4) = -2
cos (-0.5x + π/4) = -1
cos (0.5x - π/4) = -1
0.5x - π/4 = π + 2πn
0.5x = π + π/4 + 2πn
0.5x = 5π/4 + 2πn
x = 10π/4 +4πn
-------------------------------
2)2sin (π/3 - x/4) = √3
sin (π/3 - x/4) = 0.5√3
sin (-π/3 + x/4) = -0.5√3
a) (-π/3 + x/4) = -π/3 + 2πn b) (-π/3 + x/4) = -2π/3 + 2πn
x/4 = 2πn x/4 = -π/3 + 2πn
x1 = 8πn n∈Z x2 = -4π/3 + 8πn n∈Z
2х² + 6х = 0
х * (2х + 6) = 0
х₁ = 0
2х + 6 = 0
2х = -6
х₂ = -6 : 2
х₂ = -3
Ответ: х₁ = 0
х₂ = -3
1)
5x = 12.5
x = 2.5
2)
2x = 5
x = 2.5
3)
4x - 7x + 2 = 17
-3x = 15
x = -5
У=-2х+5
х=-1;4
у=-2×(-1)+5=2+5=7
у=7
у=-2×4+5
у=-8+5=-3
2)-7=-2х+5
2х=5+7
2х=12
х=6
1=-2х+5
2х=5-1
2х=4
х=2
3) х =3
X1+x2=2/3 U x1*x2=-1/3
x1=-1/3 U x2=1