Sunday, March 10, 2013

Given the line 3x + 4y + 10 = 0 find the angle wich it makes with the axis of x an its intercepts upon the axis.

We'll write the equation of the line into the standard
form.


y = m x + n, where m is the slope and n is the y
intercept.


We know that m = tan a, where a is the angle
made by the line with the axis of X.


We'll re-write the
equation of the line:


y = tan a*x +
n


We'll put the equation 3x + 4y + 10 = 0 in the standard
form. For this reason, we'll isolate 4y to the left side. We'll subtract 3x + 10 both
sides:


4y = -3x - 10


We'll
divide by 4:


y = -3x/4 -
10/4


y = -3x/4 - 5/2


The angle
made by the line with the axis of X is m = tan a.


We'll
identify m = -3/4


tan a =
-3/4


a = arctan (-3/4) +
k*pi


a = - arctan (3/4) +
k*pi


The x intercept of the line is found when y =
0


But y = -3x/4 - 5/2


-3x/4 -
5/2 = 0


We'll add 5/2 both
sides:


-3x/4 = 5/2


We'll cross
multiply and we'll get:


-6x =
20


We'll divide by -6:


x =
-20/6


x =
-10/3


So the line is intercepting x axis in
the point (-10/3 , 0).


When the line is
intercepting y axis, x = 0


So, y intercept is
n = -5/2.


So the line is
intercepting y axis in the point (0 , -5/2).

No comments:

Post a Comment

How is Anne's goal of wanting "to go on living even after my death" fulfilled in Anne Frank: The Diary of a Young Girl?I didn't get how it was...

I think you are right! I don't believe that many of the Jews who were herded into the concentration camps actually understood the eno...