Final answer:
To solve the equation 12cos(2x+2π)=21 in the interval [0,2π), divide both sides by 12, apply the inverse cosine function, subtract 2π, and divide by 2 to find x.
Step-by-step explanation:
To solve the equation 12cos(2x+2π)=21 in the interval [0,2π), we need to isolate the cosine term and then solve for x.
Step 1: Divide both sides of the equation by 12: cos(2x+2π) = 21/12 = 7/4.
Step 2: Apply the inverse cosine function to both sides to get rid of the cosine: 2x+2π = arccos(7/4).
Step 3: Subtract 2π from both sides: 2x = arccos(7/4) - 2π.
Step 4: Divide both sides by 2: x = (1/2)(arccos(7/4) - 2π).
The values of x that satisfy the equation in the interval [0,2π) can be found by plugging in the values of arccos(7/4) and 2π into the expression for x.