I need help breaking this down

Answer:
see explanation
Step-by-step explanation:
Given
2cosΘ - [tex]\sqrt{2}[/tex] = 0 ( add [tex]\sqrt{2}[/tex] to both sides )
2cosΘ = [tex]\sqrt{2}[/tex] ( divide both sides by 2 )
cosΘ = [tex]\frac{\sqrt{2} }{2}[/tex]
Since cosΘ > 0 then Θ is in first and fourth quadrants, hence
Θ = [tex]cos^{-1}[/tex] ( [tex]\frac{\sqrt{2} }{2}[/tex] ) = [tex]\frac{\pi }{4}[/tex]
OR
Θ = 2π - [tex]\frac{\pi }{4}[/tex] = [tex]\frac{7\pi }{4}[/tex]
solutions are Θ = [tex]\frac{\pi }{4}[/tex], [tex]\frac{7\pi }{4}[/tex]
Answer:
π/4, 7π/4.
Step-by-step explanation:
2 cos O - √2 = 0
2 cos O = √2
cos O = √2/2
This is an angle in 45-45-90 triangle where the sides are in the ratio
1:1:√2 where the cosine of 45 degrees = 1 /√2 = √2/2.
In radians it is π/4.
The cosine is also positive in the fourth quadrant so the other solution is
7π/4.