Question

Write the point-slope form of the line that passes through the points (-2, 1) and (0, 1). Identify (x1, y1) as (-2, 1).

Answer 1

$\bf \begin{array}{ccccccccc} &&x_1&&y_1&&x_2&&y_2\\ % (a,b) &&(~ -2 &,& 1~) % (c,d) &&(~ 0 &,& 1~) \end{array} \\\\\\ % slope = m slope = m\implies \cfrac{\stackrel{rise}{ y_2- y_1}}{\stackrel{run}{ x_2- x_1}}\implies \cfrac{1-1}{0-(-2)}\implies \cfrac{1-1}{0+2}\implies \cfrac{0}{2}\implies 0 \\\\\\ % point-slope intercept \stackrel{\textit{point-slope form}}{y- y_1= m(x- x_1)}\implies y-1=0[x-(-2)]\implies y-1=0(x+2)$