Cosine and sine of an angle θ are defined to be the x and y-coordinates of the point P on the unit circle with the property that the line from O to P makes and angle θ with the positve x-axis. cos(θ) ...

Many students think they've solved a trig equation when they get one answer (one size of angle \(x^\circ\)). However there's often more than one answer expected so be aware of this. Let's remind ...