Answer:
y = - 3x + 11
Step-by-step explanation:
the altitude is a line from the vertex A drawn perpendicular to the opposite side BC
calculate the slope of BC using the slope formula
m = [tex]\frac{y_{2}-y_{1} }{x_{2}-x_{1} }[/tex]
with (x₁, y₁ ) = B (- 7, 3 ) and (x₂, y₂ ) = C (- 1, 5 )
[tex]m_{BC}[/tex] = [tex]\frac{5-3}{-1-(-7)}[/tex] = [tex]\frac{2}{-1+7}[/tex] = [tex]\frac{2}{6}[/tex] = [tex]\frac{1}{3}[/tex]
given a line with slope m then the slope of a line perpendicular to it is
[tex]m_{perpendicular}[/tex] = - [tex]\frac{1}{m}[/tex] = - [tex]\frac{1}{\frac{1}{3} }[/tex] = - 3
the equation of a line in slope- intercept form is
y = mx + c ( m is the slope and c the y- intercept ) , then
y = - 3x + c ← is the partial equation
to find c substitute A (4, - 1 ) into the partial equation
- 1 = - 12 + c ⇒ c = - 1 + 12 = 11
y = - 3x + 11 ← equation of altitude from A
