Alejandro made an error in the steps below when determining the equation of the line that is perpendicular to the line 4x – 3y = –8 and passes through the point (3, –2).
The slope of the line given its equation is calculated through, m = -A / B. The slope of the given line is 4/3. The line perpendicular to it has the slope of -3/4. The slope-point form of the equation is,
y - y1 = m(x - x1)
where m is the slope and x1 and y1 the abscissa and ordinate of the point, respectively.
Substituting the values above,
y --2 = (-3/4)(x - 3)
Simplifying the equation gives 3x + 4y = 1.
The generic equation of the line is:
\(y-yo = m (x-xo)
\)
Where,
(xo, yo): point where the line passes
m: slope of the line
We have the following equation:
\(4x - 3y = -8
\)
Rewriting we have:
\(3y = 4x + 8
\)
\(y = (\frac{4}{3}) x + \frac{8}{3}
\)
Since the lines are perpendicular, then the slope of the line is the inverse reciprocal.
We have then:
\(m =-\frac{3}{4}
\)
The point where the line passes is:
\((xo, yo) = (3, -2)
\)
Substituting values we have:
\(y + 2 = -\frac{3}{4} (x-3)
\)
Answer:
the line that is perpendicular is:
\(y + 2= -\frac{3}{4}(x-3)
\)
Note: compare with Alejandro's steps, in order to find the error.