Question

Dada a função f(x) = 2x + 1, e seja f-1 sua função inversa, o valor de f- -1 (7) é: ​

Answer 1

$\Large\boxed{\begin{array}{l}\sf f(x)=2x+1\\\sf 2x+1=f(x)\\\sf 2x=f(x)-1\\\sf x=\dfrac{f(x)-1}{2}\\\sf f^{-1}(x)=\dfrac{x-1}{2}\\\sf f^{-1}(7)=\dfrac{7-1}{2}\\\sf f^{-1}(7)=\dfrac{6}{2}\\\sf f^{-1}(7)=3\end{array}}$