The vector w=ai+bj is perpendicular to the line ax+by=c and parallel to the line bx−ay=c. It is also true that the acute angle between intersecting lines that do not cross at right angles is the same as the angle determined by vectors that are either normal to the lines or parallel to the lines. Use this information to find the acute angle between the lines below.

2x+5y=4, 7x+3y=8

Respuesta :

Answer:

The angle between the liens is 135 degree.

Step-by-step explanation:

Equation of first line

2 x + 5 y = 4 ...... (1)

Equation of second line

7 x + 3 y = 8 ..... (2)

The slope of a line is given by

[tex]m = \frac{- coefficient of x}{coefficient of y}[/tex]

Slope of first line

[tex]m = -\frac {2}{5}[/tex]

Slope of second line

[tex]m'= - \frac{7}{3}[/tex]

The angle between the two lines is given by

[tex]tan\theta = \frac{m- m'}{1 + m m'}\\\\tan\theta = \frac{-\frac{2}{5}+\frac{7}{3}}{1+\frac{2}{5}\times \frac{7}{3}}\\\\tan\theta = -1 \\\\\theta = 135^o[/tex]