Just a few days ago was the vernal, or spring equinox. On that day in March, of course, the night is exactly as long as the day. Six months from now is the autumn equinox, when, once again, the night ...

Given any expression of the form \(a\cos x + b\sin x\) it is better to rewrite it into one of the forms \(k\cos (x \pm \alpha )\) or \(k\sin (x \pm \alpha )\) before answering the question. From this ...

This circle has the centre at the origin and a radius of 1 unit. The point P can move around the circumference of the circle. At point P the \(x\)-coordinate is \(\cos{\theta}\) and the ...