Question

nas funções reais f e g , definidas por f(x)=x^2-x-2, e g(x)=1-2x , obtenha as leis que definem :a) fogb) gof

Answer 1

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Solução!

$f(x)= x^{2} -x-2\\\\\\\ g(x)=1-2x\\\\\\\ (fog)=(1-2x)^{2} -(1-2x)-2\\\\\\\ (fog)=(1-2x-2x+4 x^{2} )-1+2x-2\\\\\\ \boxed{(fog)= 4x^{2} -2x-2}$


$f(x)= x^{2} -x-2\\\\\\\ g(x)=1-2x\\\\\\ (gof)=1-2( x^{2} -x-2)\\\\\ (gof)=1- 2x^{2} +2x+4\\\\\\ \boxed{(gof)=- 2x^{2} +2x+5}$

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