Question

3. Podemos afirmar que o zero da função f(×)=-4× + 16 é igual?

b)4


a)3


d)6


c)5​

Answer 1

$\mathrm{Seja\ a\ fun\c{c}\tilde{a}o}\ f:\mathbb{R}\to\mathbb{R}\ \mathrm{tal\ que}\ f(x)=16-4x.$

$\mathrm{O\ chamado}\ \mathbf{zero\ da\ fun\c{c}\tilde{a}o}\ \mathrm{\acute{e}\ obtido}\ \text{igualando-se}\ f(x)\ \text{a zero.}$

$f(x)=0\Longrightarrow 16-4x=0\Longrightarrow x=\dfrac{16}{4}\ \therefore\ \boxed{x=4}$

$\mathbf{Alternativa\ B.}$