contestada

What is an equation of the line that is perpendicular to 3x+y=−5 and passes through the point (3, −7) ?

Respuesta :

Answer:

y = [tex]\frac{1}{3}[/tex] x - 8

Step-by-step explanation:

the equation of a line in slope-intercept form is

y = mx + c ( m is the slope and c the y-intercept )

rearrange 3x + y = - 5 into this form

subtract 3x from both sides

y = - 3x - 5 ← in slope-intercept form

with slope m = - 3

given a line with slope m then the slope of a lin e perpendicular to it is

[tex]m_{perpendicular}[/tex] = - [tex]\frac{1}{m}[/tex], hence

[tex]m_{perpendicular}[/tex] = - [tex]\frac{1}{-3}[/tex] = [tex]\frac{1}{3}[/tex]

y = [tex]\frac{1}{3}[/tex] x + c ← is the partial equation

to find c substitute (3, - 7 ) into the partial equation

- 7 = 1 + c ⇒ c = - 7 - 1 = - 8

y = [tex]\frac{1}{3}[/tex] x - 8 ← equation of perpendicular line