The cos of 225 degrees equals the x-coordinate(-0.7071) of the point of intersection (-0.7071, -0.7071) of unit circle and r.Rotate ‘r’ anticlockwise to form 225° angle with the positive x-axis.To find the value of cos 225 degrees using the unit circle:

We can find the value of cos 225 degrees by: The value of cos 225° is given as -0.70710. The cosine function is negative in the 3rd quadrant. Note: Since, cosine is an even function, the value of cos(-225°) = cos(225°). Since the cosine function is a periodic function, we can represent cos 225° as, cos 225 degrees = cos(225° + n × 360°), n ∈ Z. Since cosine function is negative in the third quadrant, thus cos 225° value = -(1/√2) or -0.7071067. We know, using degree to radian conversion, θ in radians = θ in degrees × ( pi/180°)

Cos 225 degrees can also be expressed using the equivalent of the given angle (225 degrees) in radians (3.92699. The value of cos 225 degrees in decimal is -0.707106781.

In this article, we will discuss the methods to find the value of cos 225 degrees with examples.

Convert 225 degrees to radians