Question

O conjunto solução da inequação 9- x elevado a 2 > 0 é

Answer 1

$\Large\boxed{\begin{array}{l}\sf 9-x^2>0\\\underline{\boldsymbol{fac_{\!\!,}a\!:}} \\\sf f(x)=9-x^2\\\underline{\rm zeros\,de\,f(x):}\\\sf 9-x^2=0\\\sf x^2=9\\\sf x=\pm\sqrt{9}\\\sf x=\pm3\\\underline{\rm estudo\,do\,sinal\,de\,f(x):}\\\sf f(x)=9-x^2\\\sf a=-1<0\longrightarrow concavidade\,para\,baixo\\\sf f(x)>0\iff -3<x<3\\\sf f(x)<0\iff x<-3~~ou~~x>3\\\sf S=\{x\in\mathbb{R}/-3<x<3\}\end{array}}$