Question

Desenhe Os Gráfico Da Função:. F(x)= - 4 x + 8​

Answer 1

$\large\boxed{\begin{array}{l}\underline{\rm Func_{\!\!,}\tilde ao\,de\,1^o\,grau}\\\sf \acute E\,toda\,func_{\!\!,}\tilde ao\,que\,assume\,a\,forma\\\sf f(x)=ax+b\,onde\,a,b\in\mathbb{R},a\ne0.\\\sf a\longrightarrow coeficiente\,angular\\\sf b\longrightarrow coeficiente\,linear\end{array}}$

$\large\boxed{\begin{array}{l}\underline{\rm Representac_{\!\!,}\tilde ao\,no\,plano\,cartesiano.}\\\sf No\,plano\,cartesiano\,sua\,representac_{\!\!,}\tilde ao\\\sf \acute e\,uma\,reta\,inclinada.\\\sf se\,a>0\longrightarrow func_{\!\!,}\tilde ao\,crescente\\\sf se\,a<0\longrightarrow func_{\!\!,}\tilde ao\,decrescente\\\sf Uma\,reta\,fica\,determinada\,por\,2\,pontos.\\\sf \acute e\,usual\,conhecer\,os\,principais\,pontos.\end{array}}$

$\large\boxed{\begin{array}{l}\underline{\rm Intersecc_{\!\!,}\tilde ao\,com\,o\,eixo\,y}\\\sf Basta\,fazer\, x=0\,e\,calcular\,o\,valor\,de\,y.\\\sf o\,ponto\,assume\,a\,forma\, A(0,y).\\\underline{\rm intersecc_{\!\!,}\tilde ao\,com\,eixo\,x}\\\sf Basta\,fazer\,y=0\,e\,calcular\,o\,valor\,de,x.\\\sf o\,ponto\,assume\,a\,forma\, B(x,0)\end{array}}$

$\large\boxed{\begin{array}{l}\sf f(x)=4x+8\\\sf a=4>0\longrightarrow func_{\!\!,}\tilde ao\,crescente\\\underline{\rm intersecc_{\!\!,}\tilde ao\,com\,eixo\,y}\\\underline{\rm fac_{\!\!,}a\,x=0}\\\sf f(0)=4\cdot0+8=8\longrightarrow A(0,8)\\\underline{\rm intersecc_{\!\!,}\tilde ao\,com\,eixo\,x}\\\underline{\rm fac_{\!\!,}a\,y=0}\\\sf 4x+8=0\\\sf 4x=-8\\\sf x=-\dfrac{8}{4}\\\\\sf x=-2\longrightarrow B(-2,0)\\\sf unindo\,os\,pontos\,trac_{\!\!,}a-se\,a\,reta\\\sf \end{array}}$