В точке пересечения с осью Х у=0.
-2х^2 - 8х + 10 = 0.
D = b^2 - 4ac = 64 - 4*(-2)*10 = 64 + 80 = 144. √D = 12.
x1 = (-b + √D)/2a = (8 + 12)/-4 = -5.
x2 = (-b - √D)/2a = (8 - 12)/-4 = 1.
(-5;0), (1;0).
В точке пересечения с осью У х=0.
у = 10.
(0;10).
1
Sin(π/4+π/4)+2sin(π/4-π/4)+4cosπ/4+2cos(π/4+3π/4)=
=sinπ/2+2sin0+4cosπ/4+2cosπ=1+2*0+4*√2/2+2*(-1)=1+0+2√2-2=2√2-1
2
sin(π/4+3π/4)+2sin(π/4-3π/4)+4cos3π/4+2cos(3π/4+3π/4)=
=sinπ+2sin(-π/2)-4cosπ/4+2cos3π/2=0+2*(-1)-4*√2/2+2*0=-2-2√2
Та пожалуйста, ван момент)))
1) x = 4 + 5y
4(4 + 5y) - 3y = -1
16 + 20y - 3y = -1
17y = -17
y = -1; x = 4 - 5 = -1
2) x = 3y - 5
2(3y - 5) - 5y = -7
6y - 10 - 5y = -7
y = 3; x = 9 - 5 = 4
3) y = 2 - 2x
3x - 5(2 - 2x) = 16
3x - 10 + 10x = 16
13x = 26
x = 2; y = 2 - 4 = -2
4) y = 3x - 15
2x + 5(3x - 15) = -7
2x + 15x - 75 = -7
17x = 68
x = 4; y = 12 - 15 = -3
5) x = 6y - 2
2(6y - 2) - 3y = 5
12y - 4 - 3y = 5
9y = 9
y = 1; x = 6 - 2 = 4
6) x = 5y - 6
5(5y - 6) - 4y = 12
25y - 30 - 4y = 12
21y = 42
y = 2; x = 10 - 6 = 4