Why Was a Loan Refused to sin2r = 2sin r?

[soroban]

Why was the identity sin2r = 2sin r refused a loan?

**
He needed a cos r (cosigner).
**

 

[masters1]

Because it needs a CosR
Sin2R = 2SinR*CosR

 

[Monoxdifly]

I was quite hyped when I saw the name soroban since in another forum someone asked about his well-being. I was going to tell him when I noticed that soroban's post was made in 2012.