Question

Вычислите y(1)-y(-2)/y(2) если y=1/x

Answer 1

$y=\frac{1}{x}\\\\\\y(1)-\frac{y(-2)}{y(2)}=\frac{1}{1}-\frac{-\frac{1}{2}}{\frac{1}{2}}=1-(-\frac{1\cdot 2}{2\cdot 1})=1+1=2\\\\\\\star \; \; \frac{y(1)-y(-1)}{y(2)}=\frac{1-(-\frac{1}{2})}{\frac{1}{2}}=\frac{\frac{3}{2}}{\frac{1}{2}}=\frac{3\cdot 2}{2\cdot 1}=3$