Question

Determine o coeficiente angular da reta que passa pelos pontos: A(√2, $\frac{-1}{7}$) e B(0,0)

Answer 1

$\left[\begin{array}{ccc}x1&y1&1\\x2&y2&1\\x&y&1\end{array}\right] = \left[\begin{array}{ccc} \sqrt{2} & \frac{-1}{7} &1\\0&0&1\\x&y&1\end{array}\right] = \frac{-x}{7}- \frac{-y \sqrt{2} }{1} = \frac{-x-7y \sqrt{2} }{7} \\ \frac{-x-7y \sqrt{2} }{7} =0 \\ -x-7y \sqrt{2}=0 \\ y= \frac{x}{-7 \sqrt{2} } = \frac{-7x \sqrt{2} }{98} \\ y=ax+b \\ b=0 \\ a= \frac{-7}{98}$