Question
Solve the equation
x={kπ3π+kπ,k∈Z
Alternative Form
x={180∘k60∘+180∘k,k∈Z
Alternative Form
x≈{kπ1.047198+kπ,k∈Z
Evaluate
cos(3π−2x)−1=−21
Move the constant to the right-hand side and change its sign
cos(3π−2x)=−21+1
Add the numbers
More Steps

Evaluate
−21+1
Reduce fractions to a common denominator
−21+22
Write all numerators above the common denominator
2−1+2
Add the numbers
21
cos(3π−2x)=21
Use the inverse trigonometric function
3π−2x=arccos(21)
Calculate
3π−2x=3π3π−2x=35π
Add the period of 2kπ,k∈Z to find all solutions
3π−2x=3π+2kπ,k∈Z3π−2x=35π+2kπ,k∈Z
Calculate
More Steps

Evaluate
3π−2x=3π+2kπ
Move the constant to the right-hand side and change its sign
−2x=3π+2kπ−3π
Subtract the terms
−2x=2kπ
Change the signs on both sides of the equation
2x=2kπ
Divide both sides
22x=22kπ
Divide the numbers
x=22kπ
Divide the numbers
x=kπ
x=kπ,k∈Z3π−2x=35π+2kπ,k∈Z
Calculate
More Steps

Evaluate
3π−2x=35π+2kπ
Move the constant to the right-hand side and change its sign
−2x=35π+2kπ−3π
Subtract the terms
−2x=34π+2kπ
Change the signs on both sides of the equation
2x=−34π+2kπ
Divide both sides
22x=2−34π+2kπ
Divide the numbers
x=2−34π+2kπ
Divide the numbers
x=−32π+kπ
Calculate
x=3π+kπ
x=kπ,k∈Zx=3π+kπ,k∈Z
Solution
x={kπ3π+kπ,k∈Z
Alternative Form
x={180∘k60∘+180∘k,k∈Z
Alternative Form
x≈{kπ1.047198+kπ,k∈Z
Show Solution
