=3x2+5x-1=x2-4x
3x2+5x-1-x2+4x=o
2x2+9x-1=o
АUB={-4, -3, 0, 2, 3, 4, 7, 8, 9}
<span>5sin^2x+4sin(п/2+x)=4
</span><span>5sin^2x + 4cosx = 4
5*(1 - cos^2x) + 4cosx - 4 = 0
</span>5 - 5cos^2x + 4cosx - 4 = 0
5cos^2x - 4cosx - 1 =
D = 16 + 4*5*1 = 36
<span>cosx = (4 -6)/10
cosx = - (1/5)
x1 = (+ -)arccos(-1/5) + 2</span>πk, k∈Z
<span>cosx = (4 + 6)/10
cosx = 1
x2 = 2</span>πn, n∈Z<span>
</span>