To solve the given functional equations, we need to find functions f and g that satisfy the following two conditions for all x,y>0:
1.
(f(x)+y−1)(g(y)+x−1)=(x+y)2
2.
(−f(x)+y)(g(y)+x)=(x+y+1)(y−x−1)
### Step 1: Analyze the First Equation
Consider the first equation:
(f(x)+y−1)(g(y)+x−1)=(x+y)2
Assume f(x)=x+c and g(y)=y+d for some constants c and d. Substitute these into the equation:
(x+c+y−1)(y+d+x−1)=(x+y)2
This simplifies to:
(x+y+c−1)(x+y+d−1)=(x+y)2
By comparing terms, we get:
x+y+c−1=x+y+d−1=x+y
Thus, c=1 and d=1.
### Step 2: Verify with the Second Equation
Now, substitute f(x)=x+1 and g(y)=y+1 into the second equation:
(−f(x)+y)(g(y)+x)=(x+y+1)(y−x−1)
Substituting f and g, we have:
(−(x+1)+y)((y+1)+x)=(x+y+1)(y−x−1)
This further simplifies to:
(y−x−1)(x+y+1)=(x+y+1)(y−x−1)
Both sides of the equation are identical, confirming our solution satisfies the second equation.
### Conclusion
The functions f(x)=x+1 and g(y)=y+1 satisfy both functional equations. Therefore, the solution is:
f(x)=x+1 and g(y)=y+1
These functions are defined and satisfy the given equations for all x,y>0.