Ask Question
5 March, 02:51

Use a calculator to solve the equation on the interval [0, 2π). Round to the nearest hundredth of a radian. sin 2x - sin x = 0 : 0, 1.05, 3.14, 5.24 1.05, 3.14, 5.24 0, 2.09, 4.19 0, 2.09, 3.14, 4.19

+1
Answers (1)
  1. 5 March, 03:26
    0
    Sin 2x - sin x=0

    Using the trigonometric identity: sin 2x=2 sinx cosx

    2 sinx cosx - sinx = 0

    Common factor sinx

    sinx (2 cosx - 1) = 0

    Two options:

    1) sinx=0

    on the interval [0,2π), the sinx=0 for x=0 and x = π=3.1416→x=3.14

    2) 2 cosx - 1=0

    Solving for cosx

    2 cosx-1+1=0+1

    2 cosx = 1

    Dividing by 2 both sides of the equation:

    (2 cosx) / 2=1/2

    cosx=1/2

    cosx is positive in first and fourth quadrant:

    First quadrant cosx=1/2→x=cos^ (-1) (1/2) →x = π/3=3.1416/3→x=1.05

    Fourth quadrant: x = 2π-π/3 = (6π-π) / 3→x=5 π/3=5 (3.1416) / 3→x=5.24

    Answer: Solutions: x=0, 1.05, 3.14, and 5.24
Know the Answer?
Not Sure About the Answer?
Find an answer to your question ✅ “Use a calculator to solve the equation on the interval [0, 2π). Round to the nearest hundredth of a radian. sin 2x - sin x = 0 : 0, 1.05, ...” in 📘 Mathematics if you're in doubt about the correctness of the answers or there's no answer, then try to use the smart search and find answers to the similar questions.
Search for Other Answers