Question
find all solutions of the equation 4cos^2x-4cosx+1=0
Answers
drwls
Let cos x = y and solve the resulting equation
4y^2 -4y +1 = 0
That equation can be rewritten
(2y-1)^2 = 0
The only solution is
y = cos x = 1/2
x = cos^-1 1/2
Which angles x have cos x = 1/2 ?
There are two solutions between x = 0 and x = 2 pi
4y^2 -4y +1 = 0
That equation can be rewritten
(2y-1)^2 = 0
The only solution is
y = cos x = 1/2
x = cos^-1 1/2
Which angles x have cos x = 1/2 ?
There are two solutions between x = 0 and x = 2 pi