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An even function is one where f(x) = f(-x)

For cosine, cos(x) = cos(-x), thus cosine is an even function.

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9y ago
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9y ago

Cosine is an even function because :

cos ( theta ) = cos ( -theta) <---------------------[ Answer ]-------------

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Q: Why is cos an even function?
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Related questions

Why does cos x equal cos -x?

cos x equals cos -x because cos is an even function. An even function f is such that f(x) = f(-x).


Cos x equals -cos x plus 1?

No, but cos(-x) = cos(x), because the cosine function is an even function.


Is it true or false that the cosine function is an odd function?

False; the cosine function is an even function as cos(-x) = -cos(x).


What is cos of a negative angle?

The cosine function is an even function which means that cos(-x) = cos(x). So, if cos of an angle is positive, then the cos of the negative of that angle is positive and if cos of an angle is negative, then the cos of the negative of that angle is negaitive.


Is sin x plus cos x an odd or even function?

Neither.


How do you graph 1 divided by 4 cos?

0.25


What is equivalant function of cos 260 degree?

cos(-100 degrees)


Express cos -155 as a function of a positive acute angle?

Cos(-155) = cos(155) = 1 - cos(180-155) = 1-cos(25).


What is the reciprocal function of sec A?

The answer is cos A . cos A = 1/ (sec A)


How would you prove left cosA plus sinA right times left cos2A plus sin2A right equals cosA plus sin3A?

You need to make use of the formulae for sin(A+B) and cos(A+B), and that cos is an even function: sin(A+B) = cos A sin B + sin A cos B cos(A+B) = cos A cos B - sin A sin B cos even fn &rarr; cos(-x) = cos(x) To prove: (cos A + sin A)(cos 2A + sin 2A) = cos A + sin 3A The steps are to work with the left hand side, expand the brackets, collect [useful] terms together, apply A+B formula above (backwards) and apply even nature of cos function: (cos A + sin A)(cos 2A + sin 2A) = cos A cos 2A + cos A sin 2A + sin A cos 2A + sin A sin 2A = (cos A cos 2A + sin A sin 2A) + (cos A sin 2A + sin A cos 2A) = cos(A - 2A) + sin(A + 2A) = cos(-A) + sin 3A = cos A + sin 3A which is the right hand side as required.


What is the minimum value that the function y equals cos x assumes?

Since the range of the cosine function is (-1,1), the function y = cos(x) assumes a minimum value of -1 for y.


What is C in trigonometry?

usually referred as the function COS