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Given cos 0 = √2/5and sin 0 < 0.
What is the value of sin ?

User Ziggystar
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Answer:
Since cos 0 is positive (i.e. √2/5 > 0), we know that 0 is in the first or fourth quadrant of the unit circle.

Since sin 0 is negative (i.e. sin 0 < 0), we know that 0 is in the third or fourth quadrant of the unit circle.

In the first quadrant, both sine and cosine are positive, so that cannot be the case.

Therefore, 0 must be in the fourth quadrant of the unit circle, where cosine is positive and sine is negative.

Using the Pythagorean identity, we can find the value of sine:

sin^2 0 + cos^2 0 = 1
sin^2 0 + (√2/5)^2 = 1
sin^2 0 + 2/5 = 1
sin^2 0 = 3/5
sin 0 = ±√(3/5)

Since we know that sin 0 is negative, we take the negative root:

sin 0 = -√(3/5)

Therefore, the value of sin 0 is -√(3/5).

- I Hope This Helps! :)
User Knowband Plugins
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