Find all values of x such that sin(2x) sin(x) = 0 for 0 ≤ x < 2π

To solve the equation sin(2x) sin(x) = 0, we start by recognizing that a product of two factors is zero if at least one of the factors is zero. Therefore, we need to set each factor equal to zero separately:

1. Setting sin(2x) = 0:

The sine function equals zero at integer multiples of π:

sin(2x) = 0 → 2x = nπ, where n is an integer.

Dividing both sides by 2 gives us:

x = nπ/2.

For 0 ≤ x < 2π, the integer values for n that will keep x in this range are n = 0, 1, 2, 3, and 4. Therefore:

  • n = 0: x = 0
  • n = 1: x = π/2
  • n = 2: x = π
  • n = 3: x = 3π/2
  • n = 4: x = 2π

Thus, the solutions from this equation are:

  • x = 0
  • x = π/2
  • x = π
  • x = 3π/2
  • x = 2π

2. Setting sin(x) = 0:

Similarly, the sine function equals zero at integer multiples of π:

sin(x) = 0 → x = mπ, where m is an integer.

For 0 ≤ x < 2π, the integer values for m that will keep x in this range are m = 0, 1, and 2. Therefore:

  • m = 0: x = 0
  • m = 1: x = π
  • m = 2: x = 2π

Thus, the solutions from this equation are:

  • x = 0
  • x = π
  • x = 2π

Final Solutions:

Combining both sets of solutions, we have:

  • x = 0
  • x = π/2
  • x = π
  • x = 3π/2
  • x = 2π

So, the complete set of solutions for the equation sin(2x) sin(x) = 0 in the interval [0, 2π) is:

  • x = 0
  • x = π/2
  • x = π
  • x = 3π/2

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