Apply the reference angle by finding the angle with equivalent trig values in the first quadrant. Make the expression negative because cosine is negative in the third quadrant. The exact value of cos(30) cos (30) is √3 2 3 2. The result can be shown in multiple forms. −0.86602540… - …

Cos 210 degrees is the value of cosine trigonometric function for an angle equal to 210 degrees. Understand methods to find the value of cos 210 degrees with examples and FAQs.

Use our cos (x) calculator to find the cosine of 210 degrees - cos (210 °) - or the cosine of any angle in degrees and in radians.

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Use \cos (x+y)=\cos (x)\cos (y)-\sin (y)\sin (x) where x=180 and y=30 to obtain the result.

Finding the value of cos 210 ∘ cos 210 ∘ can be expressed as cos 210 ∘ = cos (180 ∘ + 30 ∘) [∵ c o s (180 + x) = - c o s x] = - cos 30 ∘ = - 3 2 Hence the value of cos 210 ∘ is - 3 2

Write cos(210∘)as cos(180∘+30∘)=cos(180∘+30∘) Use the Angle Sum identity: cos(s+t)=cos(s)cos(t)−sin(s)sin(t)=cos(180∘)cos(30∘)−sin(180∘)sin(30∘)

cos is found using Adjacent/Hypotenuse. tan is positive. 210 > 90°, so it is obtuse. cos (210) = -√ 3 /2.

If you have been looking for what is cos 210°, or if you have been wondering about cos 210 degrees in radians, then you are right here, too. In this post you can find the cos 210° value, along with identities.

Apply the reference angle by finding the angle with equivalent trig values in the first quadrant. Make the expression negative because cosine is negative in the third quadrant. The exact value of cos(30) cos (30) is √3 2 3 2. The result can be shown in multiple forms. −0.86602540… - …