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35 votes
And the diagram PT St find the slope of st

And the diagram PT St find the slope of st-example-1
User Eran Otzap
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2.1k points

1 Answer

19 votes
19 votes

You know that the lines PT and ST are perpendicular.

By definition, the slopes perpendicular lines are opposite reciprocal. This means that if the slope of a line is:


m_1=a

The slope of a perpendicular line to that line is:


m_2=-(1)/(a)

Knowing that:


\begin{gathered} P\mleft(2,2\mright) \\ T\mleft(-1,-4\mright) \end{gathered}

You can find the slope of the line PT using this formula:


m=(y_2-y_1)/(x_2-x_1)

Where two points on the line are:


\begin{gathered} (x_1,y_1) \\ (x_2,y_2) \end{gathered}

In this case, you can set up that for the line PT:


\begin{gathered} y_2=-4_{} \\ y_1=2 \\ \\ x_2=-1 \\ x_1=2 \end{gathered}

Then, substituting values into the formula and evaluating, you get:


m_(PT)=(-4-2)/(-1-2)=(-6)/(-3)=2

Knowing the slope of PT, you can determine that the slope of ST is:


m_(ST)=-(1)/(2)

Hence, the answer is:


m_(ST)=-(1)/(2)
User Sean Glover
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