Why Does the Solution Include √13 in the Numerator for Trigonometric Ratios?

[CrossFit415]

Ok...

(2, -3)

R = (Sqrt x^2 + y^2)
R = (sqrt (2)^2 + (-3)^2)
R= (sqrt 13)^2
R=13

Sin = y/r

Sin -3 / 13 ?

Cosin 2 / 13 ?

But then.. how come the answer gives me sin -3 (sqrt13) / 13 and for cosin 2(sqrt13) / 13

My question is how come there's a (sqrt13) included for the numerator since r = 13 ?

 

[tiny-tim]

Hi CrossFit415!

(have a square-root: √ and try using the X² icon just above the Reply box )

R = (sqrt (2)^2 + (-3)^2)
R= (sqrt 13)^2

You've porbably worked it out by now,

but that should be just R = √(4 + 9) = √(13).