Question 746610
Find the solution of the equation in the interval [0,2pi) algebraically. 
sin^2x+cosx+1=0
1-cos^2x+cosx+1=0
cos^2x-cosx-2=0
(cosx-2)(cosx+1)=0
cosx=2 (reject,(-1 &#8804; cosx &#8804; 1))
or
cosx=-1
x=&#960;