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C2 Trigonometric Functions

Can anyone help me with how to find the value of sin(-180) for example without using a calculator please?
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Imagine a unit circle (radius 1, centred on the origin 0,0). Starting from the positive x-axis (or 'east' direction) go anticlockwise however many degrees you want to. If it's negative angle then go clockwise. The sin axis is the y axis and the cos axis is the x axis. So sin(-180) would therefore be 0. It's also useful to just memorise the shapes of the graphs of sin and cos as they are very common functions throughout a level.

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