The point [tex]\( P \)[/tex] is on the unit circle. If the [tex]\( y \)[/tex]-coordinate of [tex]\( P \)[/tex] is [tex]\(-\frac{4}{8}\)[/tex], and [tex]\( P \)[/tex] is in quadrant III, find [tex]\( x \)[/tex].

Round your answer to one decimal place.

[tex]\[ x = \][/tex]



Answer :

Given that point [tex]\(P\)[/tex] is on the unit circle, has a [tex]\(y\)[/tex]-coordinate of [tex]\(-\frac{4}{8}\)[/tex], and lies in quadrant III, let's find the corresponding [tex]\(x\)[/tex]-coordinate.

1. Determine the given [tex]\(y\)[/tex]-coordinate:
[tex]\[ y = -\frac{4}{8} = -0.5 \][/tex]

2. Calculate [tex]\(y^2\)[/tex]:
[tex]\[ y^2 = (-0.5)^2 = 0.25 \][/tex]

3. Use the unit circle equation [tex]\(x^2 + y^2 = 1\)[/tex] to solve for [tex]\(x^2\)[/tex]:
[tex]\[ x^2 + 0.25 = 1 \][/tex]
[tex]\[ x^2 = 1 - 0.25 \][/tex]
[tex]\[ x^2 = 0.75 \][/tex]

4. Take the square root to determine [tex]\(x\)[/tex]. Since [tex]\(P\)[/tex] is in quadrant III, [tex]\(x\)[/tex] will be negative:
[tex]\[ x = -\sqrt{0.75} \][/tex]

5. Simplify and round the result to one decimal place:
[tex]\[ x = -\sqrt{0.75} \approx -0.866 \approx -0.9 \][/tex]

So, the [tex]\(x\)[/tex]-coordinate of point [tex]\(P\)[/tex] is:
[tex]\[ x = -0.9 \][/tex]