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Find the exact value of sin (2x) if tan(x)=-1/5.

User CharlieB
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Answer: The value of sin(2x) can be found using the identity:

sin(2x) = 2sin(x)cos(x)

Since tan(x) = -1/5, we can use the tangent definition to find the sine and cosine values:

tan(x) = sin(x) / cos(x) = -1/5

Cross multiplying and solving for sin(x), we get:

sin(x) = -5 / sqrt(26)

And using the Pythagorean identity:

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

We can find cos(x):

cos(x) = sqrt(1 - sin^2(x)) = sqrt(1 - (-5/sqrt(26))^2) = sqrt(26) / sqrt(26) = sqrt(26) / sqrt(26) = sqrt(26) / 5

Finally, substituting the values of sin(x) and cos(x) into the formula for sin(2x), we get:

sin(2x) = 2sin(x)cos(x) = 2 * (-5 / sqrt(26)) * (sqrt(26) / 5) = -2 sqrt(26) / 5 = -2 sqrt(26) / 5 = -2 sqrt(26) / 5

So the exact value of sin(2x) is -2 sqrt(26) / 5.

Explanation:

User Gcb
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