Sin^2x + 3cosx - 3 = 0

Question

Sin^2x + 3cosx - 3 = 0

Answer 1

Sin^2(x)=1-cos^2(x)
1-cos^2(x)+3cos(x)-3=0
-cos^2(x)+3cos(x)-2=0
cos^2(x)-3cos(x)+2=0
D=9-8=1
x1=(3+1)/2=2
x2=(3-1)/2=1
Ответ: 1 и 2.