<span>х</span>²<span> + bх – 6 = 0
-6*x2=-6
x2=-6:(-6)
x2=1
b=-(x1+x2)=b=-(-6+1)
b=5</span>
а)√2cos^2(x)=sin(x-п/2)
√2cos^2(x)+cosx=0
cosx(√2cosx+1)=0
cosx=0 или cosx=-1/√2
x=п/2+пk, x=+-3п/4+2пk;
б) -3п/2;-3п/4.
Ответ: а)x=п/2+пk, x=+-3п/4+2пk;
б)-3п/2;-3п/4.