C(d-5)+6(d-5)= (c+6)(d-5)
<span>bx-by+4x-4y=b(x-y)+4(x-y)=(b+4)(x-y)</span>
<span> (sin (3x/2)+ cos(3x\2))^2=1\2</span>
<span>sin^2(3x/2)+2sin3x/2cos3x/2+cos^2(3x/2)=1/2</span>
<span>1+sin3x=1/2</span>
<span>sin3x=-1/2</span>
<span>3x=(-1)^(n+1)*pi/6+pi n</span>
<span>x=(-1)^(n+1)*pi/18+1/3pi n</span>
Sin2x + 1 = Cosx + 2Sinx
Sin2x - 2Sinx + 1 - Cosx = 0
(2SinxCosx - 2Sinx) + (1 - Cosx) = 0
2Sinx(Cosx - 1) - (Cosx - 1) = 0
(Cosx - 1)(2Sinx - 1) = 0