100k views
5 votes
PLEASE HELP
L has y-intercept (0,5) and is perpendicular to the line with equation y=1/3x+1

PLEASE HELP L has y-intercept (0,5) and is perpendicular to the line with equation-example-1

1 Answer

4 votes

Answer:

y=-3x+5

Explanation:

Given a line L such that:

• L has y-intercept (0,5); and

,

• L is perpendicular to the line with equation y=(1/3)x+1.

We want to find the equation of the line in the slope-intercept form.

The slope-intercept form of the equation of a straight line is given as:


\begin{equation} y=mx+b\text{ where }\begin{cases}m={slope} \\ b={y-intercept}\end{cases} \end{equation}

Comparing the given line with the form above:


y=(1)/(3)x+1\implies Slope,m=(1)/(3)

Next, we find the slope of the perpendicular line L.

• Two lines are perpendicular if the product of their slopes is -1.

Let the slope of L = m1.

Since L and y=(1/3)x+1 are perpendicular, therefore:


\begin{gathered} m_1*(1)/(3)=-1 \\ \implies Slope\text{ of line L}=-3 \end{gathered}

The y-intercept of L is at (0,5), therefore:


y-intercept,b=5

Substitute the slope, m=-3, and y-intercept, b=5 into the slope-intercept form.


\begin{gathered} y=mx+b \\ y=-3x+5 \end{gathered}

The equation of line L is:


y=-3x+5

User Brandon Kelly
by
5.1k points