Question

Escreva a função afim f(x)=ax+b sabendo que.
a) f(1) e f(3)=7

Answer 1

Bom dia! 

Escreva a função afim f(x)=ax+b sabendo que.
a) f(1) e f(3)=7

$f(1)= 7 \to (1,7) \qquad\qquad f(3)=7\to (3, 7) \\ \\ \\ \dfrac{y-y_1}{x-x_1}= \dfrac{y_2-y_1}{x_2-x_1} \qquad x_1= 1\quad y_1= 7\quad x_2=3\quad y_2= 7 \\ \\ \\ \dfrac{y-7}{x-1}= \dfrac{7-7}{3-1} \\ \\ \\ \dfrac{y-7}{x-1}= \dfrac{0}{2} \\ \\ \\ \dfrac{y-7}{x-1}= 0 \\ \\ \\ y-7= 0*{(x-1)} \\ \\ \\ y-7= 0\qquad\to\qquad \boxed{y=7}\to \boxed{f(x)=ax+b\to f(x)= 7}$