+14995 sin^2(x) + cos(x) + 1 = 0 In the interval [0, 2π)
\(sin^2(x)+cos(x)+1=0\)
\(sin^2(x)=1-cos^2(x)\)
\(1-cos^2(x)+cos(x)+1=0\)
\(cos^2(x)-cos(x)-2=0\)
cos(x)=a
\(a^2-1a-2=0\)
p q
\(a=-\frac{p}{2}\pm\sqrt{(\frac{p}{2})^2-q}\)
\(a=\frac{1}{2}\pm\sqrt{(\frac{1}{2})^2+2}\)
\(a=\frac{1}{2}\pm1.5\)
\(a_1=2\\cos(x)=2\\deleted \)
\(a_2=\frac{1}{2}-1.5\\cos(x)=-1\\x=arc\ cos (-1)\)
\(\large x=\pi\\or\\x=180°\)
!
