Hello Savior_Self Originally Posted by
Savior_Self I actually dunno what the identities for $\displaystyle \cot^2$ are...
There are three identities like this, and they all start with Pythagoras' Theorem:$\displaystyle \text O^2+\text A^2 = \text H^2$
Divide both sides by $\displaystyle \text H^2$:$\displaystyle \sin^2\theta + \cos^2\theta = 1$ (Do you see? $\displaystyle \sin^2\theta = \frac{\text O^2}{\text H^2}$ ... etc)
Instead, divide by $\displaystyle \text A^2$:$\displaystyle \tan^2\theta+1 = \sec^2\theta$
Now divide by $\displaystyle \text O^2$:$\displaystyle 1+\cot^2\theta = \csc^2\theta$
Perhaps that will help you remember them!
Grandad