Cos1230°

The value of cos(1230°) can be found using the unit circle.

First, let's convert 1230° to its equivalent angle within one full revolution (360°). We can do this by dividing 1230° by 360°:

1230° ÷ 360° = 3 with a remainder of 90°

Therefore, 1230° = 3(360°) + 90°.

Next, we can use the property of periodicity of cosine to find the value of cos(1230°) by finding the value of cos(90°). On the unit circle, cos(90°) is 0.

Hence, cos(1230°) = cos(3(360°) + 90°) = cos(90°) = 0.