108k views
5 votes
Hey could anyone solve this for me and make sure its correct

Hey could anyone solve this for me and make sure its correct-example-1
User Landister
by
7.7k points

2 Answers

5 votes

Explanation:

the slope of a line is the ratio

y coordinate change / x coordinate change

when going from one point on the line to another.

the perpendicular slope is simply turning that ratio fraction upside down and flips the sign.

(5, 7) to (15, 31)

x changes by +10 (from 5 to 15).

y changes by +24 (from 7 to 31).

the slope (or gradient) is therefore

+24/+10 = 12/5

the perpendicular slope or gradient is then

-5/12

User Pili
by
7.4k points
4 votes

the slope goes by several names

• average rate of change

• rate of change

• deltaY over deltaX

• Δy over Δx

• rise over run

• gradient

• constant of proportionality

however, is the same cat wearing different costumes.

to get the slope of any straight line, we simply need two points off of it, let's use those provided


R(\stackrel{x_1}{5}~,~\stackrel{y_1}{7})\qquad S(\stackrel{x_2}{15}~,~\stackrel{y_2}{31}) ~\hfill \stackrel{slope}{m}\implies \cfrac{\stackrel{\textit{\large rise}} {\stackrel{y_2}{31}-\stackrel{y1}{7}}}{\underset{\textit{\large run}} {\underset{x_2}{15}-\underset{x_1}{5}}} \implies \cfrac{ 24 }{ 10 } \implies \cfrac{12 }{ 5 }

keeping in mind that perpendicular lines have negative reciprocal slopes


\stackrel{~\hspace{5em}\textit{perpendicular lines have \underline{negative reciprocal} slopes}~\hspace{5em}} {\stackrel{slope}{ \cfrac{12}{5}} ~\hfill \stackrel{reciprocal}{\cfrac{5}{12}} ~\hfill \stackrel{negative~reciprocal}{ {\Large \begin{array}{llll} -\cfrac{5}{12} \end{array}} }}

User EFL
by
8.1k points