Explicație pas cu pas:
a)
[tex]f(x) = 2x + 4[/tex]
[tex]f( - \frac{1}{2} ) = 2 \times ( - \frac{1}{2}) + 4 = - 1 + 4 = 3[/tex]
[tex]f(\frac{1}{2} ) = 2 \times \frac{1}{2} + 4 = 1 + 4 = 5[/tex]
[tex]f(\frac{1}{2} ) - f(\frac{1}{2} ) = 3 - 5 = - 2[/tex]
b)
[tex]2x - y + 4 = 0[/tex]
[tex]d(O;Gf) = \frac{ |2 \times 0 + ( - 1) \times 0 + 4| }{ \sqrt{ {2}^{2} + {( - 1)}^{2} }}= \frac{ |4| }{ \sqrt{4 + 1} } = \frac{4}{ \sqrt{5} } = \frac{4 \sqrt{5} }{5} [/tex]
