Question

The arithmetic mean a square + b square is equal to to a square minus b square

Answer 1

$\frac{a}{2}$

Step-by-step explanation:

${a}^{2} + {b}^{2} = {a}^{2} - {b}^{2} \\ {b}^{2} = - {b}^{2} \\ {b}^{2} + {b}^{2} = 0\\ 2 {b}^{2} = 0 \\ {b}^{2} = 0 \\ b = 0 \\ {a}^{2} + {0}^{2} = {a}^{2} - {0}^{2} \\ {a}^{2} = {a}^{2} \\ a \: is \: a \: real \: number \\ mean \: = \frac{a + b}{2} = \frac{a + 0}{2} = \frac{a}{2}$