contestada

the straight line L, has equation y=3x-4 The straight line 1, in perpendicular to L, and passes through the point (9.5) Find an equation of line L

Respuesta :

Given:

The equation of given line is

[tex]y=3x-4[/tex]

A line is perpendicular to the given line and passes through the point (9,5).

To find:

The equation of the perpendicular line.

Solution:

We have,

[tex]y=3x-4[/tex]

On comparing this equation with slope intercept form [tex]y=mx+b[/tex], we get

[tex]m=3[/tex]

It means, the slope of the given line is 3.

The product of slopes of two perpendicular lines is -1.

[tex]m\times m_1=-1[/tex]

[tex]3\times m_1=-1[/tex]

[tex]m_1=-\dfrac{1}{3}[/tex]

Point slope form of a line is

[tex]y-y_1=m(x-x_1)[/tex]

Where, m is the slope.

The slope of perpendicular line is [tex]-\dfrac{1}{3}[/tex] and it passes through the point (9,5). So the equation of the line is

[tex]y-5=-\dfrac{1}{3}(x-9)[/tex]

[tex]y-5=-\dfrac{1}{3}(x)-\dfrac{1}{3}(-9)[/tex]

[tex]y-5=-\dfrac{1}{3}x+3[/tex]

Adding 5 on both sides, we get

[tex]y-5+5=-\dfrac{1}{3}x+3+5[/tex]

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

Therefore, the equation of required line is [tex]y=-\dfrac{1}{3}x+8[/tex].