Question

Função

sabendo que f (6)= 10, é correto afirmar que o valor de f (-4) é?

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Answer 1

$\sf{x_V=-\dfrac{b}{2a}}\\\sf{1=-\dfrac{b}{2a}\implies~b=-2a}$

$\sf{f(x)=ax^2+bx+c}\\\sf{f(x)=ax^2-2ax+c}\\\sf{f(6)=a\cdot6^2-2a\cdot6+c}\\\sf{36a-12a+c=10}\\\sf{24a+c=10}$

$\sf{f(-4)=a\cdot(-4)^2-2a\cdot(-4)+c}\\\sf{16a+8a+c}\\\sf{f(-4)=24a+c}\\\huge\boxed{\boxed{\boxed{\boxed{\sf{f(-4)=10~\checkmark}}}}}\\\huge\boxed{\boxed{\boxed{\boxed{\sf{\maltese~~alternativa~~c}}}}}$