Find the cubic equation whose roots are the radius of three inscribed circles in term of inradiu, circumradius and perimeter.

Explanation

To find the cubic equation whose roots are the radii of the three inscribed circles in terms of the inradius (R), circumradius (R), and perimeter (S), we can follow these steps:

### Step 1: Define the Roots
Let the roots of the cubic equation be \( R_1, R_2, R_3 \), where:
- \( R_1 \) is the inradius \( r \)
- \( R_2 \) is the circumradius \( R \)
- \( R_3 \) is the semiperimeter \( S \)

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