Find the Exact Value of Arccos Sin: Explain Your Reasoning

To find the exact value of arccos(sin(x)), we first need to understand the range and definitions of the functions involved.

The sin(x) function gives us the sine of an angle x, which ranges from -1 to 1 for all real values of x. The arccos(y) function, on the other hand, is defined for y values in the range of -1 to 1 and returns an angle in the range from 0 to π (0 to 180 degrees).

Let's consider when we're asked to find arccos(sin(x)): this expression will essentially yield an angle whose cosine is equal to sin(x). To analyze this further, we can use the identity:

sin^2(x) + cos^2(x) = 1

From this identity, we can see that cos(x) = sqrt(1 - sin^2(x)) when discussing angles in the first quadrant.

However, we need to consider multiple cases based on the value of x to be precise. For instance:

  • If x is in the first quadrant (0 to π/2), then sin(x) = sin(x), and arccos(sin(x)) typically gives us the angle from 0 to π/2.
  • If x is in the second quadrant (π/2 to π), then sin(x) is still positive but arccos(sin(x)) will yield a different angle.
  • If x is in the third quadrant (π to 3π/2), then sin(x) is negative, and in this case, the arccos function would still give us an angle in the correct range that corresponds to the negative sine.
  • If x is in the fourth quadrant (3π/2 to 2π), again, we have a negative sine value.

In general, what we can summarize is that depending on the quadrant where angle x exists, the arccos(sin(x)) will return an angle which can be calculated based on the value of sin(x). The values will range accordingly from various intervals of angles based on the periodic nature of sine and cosine functions.

For practical purposes, if you need a specific value, just substitute for x (making sure it’s within a recognizable range for simplicity) to find direct results.

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