Question 285807
x=(1/2)sqrt(2a^2+b^2-c^2)
2x=sqrt(2a^2+2b^2-c^2)
4x^2= (2a^2+2b^2-c^2)
x^2= (2a^2+2b^2-c^2)/4
x^2=(a^2+b^2-c^2)/2
so to be equal x^2 must be ab
can you take it from here?