Question

17. Determine o valor de m para que o gráfico da
função f(x) = 2x + m - 3:
a) intersecte o eixo y no ponto (0,5);
b) intersecte o eixo x no ponto (3, 0).​

Answer 1

f(x)  =  y  =  2x + m - 3

a)

Vamos substituir o par ordenado na função:

$(x,y)~=~(0\,,\,5):\\\\\\y~=~2x~+~m~-~3\\\\\\5~=~2~.~0~+~m~-~3\\\\\\5~=~0~+~m~-~3\\\\\\m~=~5~+~3\\\\\\\boxed{m~=~8}$

b)

Vamos substituir o par ordenado na função:

$(x,y)~=~(3\,,\,0):\\\\\\y~=~2x~+~m~-~3\\\\\\0~=~2~.~3~+~m~-~3\\\\\\0~=~6~+~m~-~3\\\\\\m~=\,-6~+~3\\\\\\\boxed{m~=\,-3}$