44.1k views
0 votes
What is the equation of the perpendicular to y=2/3x+1 that passes through the point (12,-6)

1 Answer

4 votes
well, first off let's check what is the slope of y = 2/3x+1.... .hmmmmm, notice
\bf y=\stackrel{slope}{\cfrac{2}{3}}x+1 , since the equation is already in slope-intercept form, we can see it has a slope of 2/3.

well then, a line perpendicular to that one, will have a negative reciprocal to it.


\bf \textit{perpendicular, negative-reciprocal slope for slope}\quad \cfrac{2}{3}\\\\ slope=\cfrac{2}{{{ 3}}}\qquad negative\implies -\cfrac{2}{{{ 3}}}\qquad reciprocal\implies - \cfrac{{{ 3}}}{2}

so, we're really looking for the equation of a line whose slope is -3/2 and goes through 12, -6.


\bf \begin{array}{lllll} &x_1&y_1\\ % (a,b) &({{ 12}}\quad ,&{{ -6}}) \end{array} \\\\\\ % slope = m slope = {{ m}}= \cfrac{rise}{run} \implies -\cfrac{3}{2} \\\\\\ % point-slope intercept \stackrel{\textit{point-slope form}}{y-{{ y_1}}={{ m}}(x-{{ x_1}})}\implies y-(-6)=-\cfrac{3}{2}(x-12) \\\\\\ y+6=-\cfrac{3}{2}x+18\implies y=-\cfrac{3}{2}x+12
User Allenhwkim
by
8.0k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories