Find all solutions to the equation in the interval [0, 2π). cos x = sin 2x
Solution:
Given, cos x = sin 2x
We have to find the solutions to the equation in the interval (0, 2π).
We know, sin 2x = 2 sin x cos x
So, cos x = 2 sin x cos x
The equation can be rewritten as
2 sin x cos x - cos x = 0
cos x(2 sin x - 1) = 0
Now, cos x = 0
x = cos⁻¹(0)
x = π/2 and 3π/2
2 sin x - 1 = 0
2 sin x = 1
sin x = 1/2
x = sin⁻¹(1/2)
x = π/6 and 5π/6
Therefore, the values of x are π/2, 3π/2, π/6 and 5π/6.
Find all solutions to the equation in the interval [0, 2π). cos x = sin 2x
Summary:
All solutions to the equation in the interval [0, 2π). cos x = sin 2x are π/2, 3π/2, π/6 and 5π/6.
Math worksheets and
visual curriculum
visual curriculum