Answer: x = 115.5°
Step-by-step explanation:
I suppose that we have the equation:
2*cos(x + 40°) = 1/2 for 0° < x < 360°
Let's solve this.
First, we isolate the cosine function:
cos(x + 40°) = (1/2)/2 = 1/4
cos(x + 40°) = 1/4
Now we can use the Acos(x) function, remember that:
Acos(cos(x)) = x
cos(Acos(x)) = x
Then if we use this function in both sides, we get:
Acos( cos(x + 40°)) = Acos(1/4)
x + 40° = Acos(1/4) = 75.5°
x = 75.5° + 40° = 115.5°
x = 115.5°
