<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>
Х²+3х-4=0
Дискрименант:
х(1,2)=-3±√3²-4*1*(-4)/2*1=-3±5/2
х(1)=3+5/2=8/2=4
х(2)=3-5/2=-2/2=-1
Ответ: 4 и -1
1,(6) = (16 - 1) / 9 = 15/9 = 5/3
-6kp - 60p - 48k - 480 = -6p(k+10) - 48(k+10) = (k+10)(-6p-48) = -6(k+10)(p+8)