Question

find the mean poportional between x+y and x-y

Answer 1

the mean proportional between x+y and x-y
$\sqrt{(x+y)(x-y)}$
$\sqrt{ x^{2} - y^{2}}$
x+y : $\sqrt{ x^{2} - y^{2} }$ : : $\sqrt{ x^{2} - y^{2} }$ : x-y