To solve the equation 2cos^2(2x) - 7cos(2x) + 5 = 0, we can let y = cos(2x) and rewrite the equation as 2y^2 - 7y + 5 = 0.
Now, we can factor the quadratic equation as follows:
(2y - 5)(y - 1) = 0
Setting each factor to zero gives us:
2y - 5 = 0 or y - 1 = 0
Solving for y in each case:
Case 1: 2y - 5 = 02y = 5y = 5/2
Case 2: y - 1 = 0y = 1
Now we substitute back y = cos(2x) in terms of x:
cos(2x) = 5/2 or cos(2x) = 1
Since the cosine function has a range of [-1, 1], the equation cos(2x) = 5/2 has no real solutions.
For cos(2x) = 1, we know that the cosine function equals 1 when the angle is 0 degrees or 360 degrees. Therefore, we have:
2x = 0 + 360n, where n is an integer
Dividing by 2 on both sides gives us:
x = 0 + 180n, where n is an integer
So, the solutions to the equation 2cos^2(2x) - 7cos(2x) + 5 = 0 are x = 0 degrees + 180n degrees, where n is an integer.
To solve the equation 2cos^2(2x) - 7cos(2x) + 5 = 0, we can let y = cos(2x) and rewrite the equation as 2y^2 - 7y + 5 = 0.
Now, we can factor the quadratic equation as follows:
(2y - 5)(y - 1) = 0
Setting each factor to zero gives us:
2y - 5 = 0 or y - 1 = 0
Solving for y in each case:
Case 1: 2y - 5 = 0
2y = 5
y = 5/2
Case 2: y - 1 = 0
y = 1
Now we substitute back y = cos(2x) in terms of x:
cos(2x) = 5/2 or cos(2x) = 1
Since the cosine function has a range of [-1, 1], the equation cos(2x) = 5/2 has no real solutions.
For cos(2x) = 1, we know that the cosine function equals 1 when the angle is 0 degrees or 360 degrees. Therefore, we have:
2x = 0 + 360n, where n is an integer
Dividing by 2 on both sides gives us:
x = 0 + 180n, where n is an integer
So, the solutions to the equation 2cos^2(2x) - 7cos(2x) + 5 = 0 are x = 0 degrees + 180n degrees, where n is an integer.