Segue as instruções abaixo e aplica-as no GeoGebra abaixo:

a ferramenta mover [icon]/images/ggb/toolbar/mode_move.png[/icon]

1. Insere a função linear [math]f\left(x\right)=ax[/math]. Vai aparecer, na grelha o gráfico da função. Clica um cima da reta, de seguida nos três pontos e acede às configurações. Seleciona em "Exibir Rótulo" a opção "Nome & Valor".[br]2. Como deves ter reparado, o GeoGebra criou o parametro [u][b]a[/b][/u]. Clica em [img]data:image/png;base64,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[/img] para o tornares visível na grelha.[br][br]3. Move o parâmetro [b][u]a[/u][/b] para veres o que acontece.

1. Vamos inserir 2 pontos da reta. Usa a ferramenta [icon]/images/ggb/toolbar/mode_point.png[/icon] clicando da reta (quando a mãozinha aparecer):[br][list][*]Insere o ponto A;[/*][*]Insere o ponto B.[/*][/list]2. Em cada ponto, acede às configurações e seleciona em "Exibir Rótulo" a opção "Nome & Valor".[br][br]3. Vamos tornar visível as coordenadas dos pontos nos dois eixos:[br][list][*]Em cada ponto traça uma reta perpendicular [icon]/images/ggb/toolbar/mode_orthogonal.png[/icon] ao eixo do x e uma reta perpendicular [icon]/images/ggb/toolbar/mode_orthogonal.png[/icon] ao eixo do y.[/*][*]Encontra o ponto de interceção [icon]/images/ggb/toolbar/mode_intersect.png[/icon] dessas retas com os dois eixos.[/*][*]Esconde as retas perpendiculares.[/*][*]Desenha um segmento de reta [icon]/images/ggb/toolbar/mode_segment.png[/icon] desde cada ponto da reta até a respetiva interceção nos eixos.[/*][*]Muda esses segmentos para tracejado, nas configurações, e retira a seleção "Exibir Rótulo".[br][/*][/list]

[b][u]Definição[/u][/b][br][br]O declive [b][u]a[/u] [/b]de uma reta não vertical que passa nos pontos [math]A(x_A,y_A)[/math] e [math]B(x_B,y_B)[/math] é dado por [math]a=\frac{y_B-y_A}{x_B-x_A}[/math][br][br]Repara que [math]y_B-y_A[/math] corresponde à distância dos pontos que encontraste no eixo dos [math]yy[/math] e que [math]x_B-x_A[/math] corresponde à distância dos pontos que encontraste no eixo dos [math]xx[/math].

1. Mede [icon]/images/ggb/toolbar/mode_distance.png[/icon] a distância entre os pontos que encontraste no eixo dos [math]xx[/math] [br]2. Mede [icon]/images/ggb/toolbar/mode_distance.png[/icon] a distância entre os pontos que encontraste no eixo dos [math]yy[/math][br]3. Calcula o declive (agora temos que parar para te ensinar)[br][br]ATENÇÃO[br]O GeoGebra ao calcular o comprimento, coloca-o sempre positivo!!!![br][br]Qual é a relação entre o declive e [math]f(x)=ax[/math]?