Question

Dada a função F(x) = ax + b e sabendo-se que F(3)= 5 e F(-2) = -5. Calcule F(1/2).

Answer 1

Resposta:

$f(x)=ax+b$

$f(3)=5$   <=>  $5=3a+b$

$f(-2)=-5$  <=>  $-5=-2a+b$

$\left \{ {{3a+b=5} \atop {-2a+b=-5}} \right.$

$\left \{ {{b=5-3a} \atop {-2a+5-3a=-5}} \right.$

$\left \{ {{b=5-3a} \atop {-5a=-10}} \right.$

$\left \{ {{b=5-3a} \atop {a=2}} \right.$

$\left \{ {{b=5-3*2} \atop {a=2}} \right.$

$\left \{ {{b=-1} \atop {a=2}} \right.$

$f(x)=2x-1$

$f(\frac{1}{2} )=2*\frac{1}{2} -1<=>$

$<=>f(\frac{1}{2} )=0$