You can
put this solution on YOUR website!You have to say this one in a way that makes sense
In words:
First, "arctan(x)" means "the angle whose tangent is x"
Therefore, "2*arctan(x)" means twice the angle whose tangent is x"
Now I can read the whole thing as:
"the sine of twice the angle whose tangent is x"
If the tangent is
, then the sine is
and the cosine is
The double angle formula for sine is:
answer
Suppose the angle was 45 degrees. Then
and
and this is true
