Find the exact value of cot(15degrees) using half angle formulas?

Double angle (or half angle, depending how you look at it) identities:

So we have

Note that when taking the square root, we should take into account that that could yield two possible solutions, but we know and , so it's also the case that .

Also, the reason we have equality in the last step can be explained like so:

(not unlike the process used to complete the square)

we need the options

step-by-step explanation:

step-by-step explanation:

if you meant, "on the way from (3, 2) to (3, 14):

x does not change; y increases by 12.

ensure that you have copied down this problem correctly.   .