a parabola f(x)= -x²+5x+k passa pelo ponto (2,3). qual o valor de k ?
Soluções para a tarefa
Respondido por
2
Boa tarde!
Solução!
![f(x)=- x^{2} +5x+k\\\\\
y=- x^{2} +5x+k\\\\\\
Ponto(2,3)\\\\\\
Substituindo~~o~~ponto~~na~~equac\~ao!\\\\\\
3=- (2)^{2} +5(2)+k\\\\\\
3=-4+10+k\\\\\
3=6+k\\\\\ -3=k\\\\\
k=-3\\\\\ k=c](https://tex.z-dn.net/?f=f%28x%29%3D-+x%5E%7B2%7D++%2B5x%2Bk%5C%5C%5C%5C%5C%0Ay%3D-+x%5E%7B2%7D+%2B5x%2Bk%5C%5C%5C%5C%5C%5C%0APonto%282%2C3%29%5C%5C%5C%5C%5C%5C%0ASubstituindo%7E%7Eo%7E%7Eponto%7E%7Ena%7E%7Eequac%5C%7Eao%21%5C%5C%5C%5C%5C%5C%0A3%3D-+%282%29%5E%7B2%7D+%2B5%282%29%2Bk%5C%5C%5C%5C%5C%5C%0A3%3D-4%2B10%2Bk%5C%5C%5C%5C%5C%0A3%3D6%2Bk%5C%5C%5C%5C%5C+-3%3Dk%5C%5C%5C%5C%5C%0Ak%3D-3%5C%5C%5C%5C%5C%C2%A0k%3Dc "f(x)=- x^{2} +5x+k\\\\\
y=- x^{2} +5x+k\\\\\\
Ponto(2,3)\\\\\\
Substituindo~~o~~ponto~~na~~equac\~ao!\\\\\\
3=- (2)^{2} +5(2)+k\\\\\\
3=-4+10+k\\\\\
3=6+k\\\\\ -3=k\\\\\
k=-3\\\\\ k=c")
![f(x)=- x^{2} +5x+k\\\\\
\boxed{Resposta:f(x)=- x^{2} +5x-3}](https://tex.z-dn.net/?f=f%28x%29%3D-+x%5E%7B2%7D+%2B5x%2Bk%5C%5C%5C%5C%5C%0A%5Cboxed%7BResposta%3Af%28x%29%3D-+x%5E%7B2%7D+%2B5x-3%7D "f(x)=- x^{2} +5x+k\\\\\
\boxed{Resposta:f(x)=- x^{2} +5x-3}")
Boa tarde!
Bons estudos!
Solução!
Boa tarde!
Bons estudos!
Perguntas interessantes