Angle of Inclination of Line in Vector Equation

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SUMMARY

The discussion focuses on determining the angle of inclination of lines represented by vector equations, specifically r = (2,-6) + t(3,-4) and r = (6,1) + t(5,1). It establishes that the angle of inclination, denoted as ø, can be found using trigonometric methods or by calculating the dot product with the unit vector in the direction of the x-axis, <1,0>. Additionally, it confirms that the tangent of the angle of inclination is equivalent to the slope of the line.

PREREQUISITES
  • Understanding of vector equations in the form r = a + tb
  • Knowledge of trigonometric functions and their applications
  • Familiarity with the concept of dot products in vector mathematics
  • Basic understanding of slopes and their relationship to angles
NEXT STEPS
  • Study the calculation of angles using the dot product in vector analysis
  • Learn about the relationship between slope and angle of inclination in coordinate geometry
  • Explore trigonometric identities and their applications in finding angles
  • Investigate graphical methods for visualizing vector equations in the xy-plane
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Students studying geometry, mathematics educators, and anyone interested in vector analysis and trigonometry applications.

Cuisine123
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Homework Statement


Find the angle of inclination of each of the following lines.
i) r = (2,-6) + t(3,-4) ii) r = (6,1) + t(5,1)

B) prove that the tangent of the angle of inclination is equal to the slope of the line.


Homework Equations


N/A

The Attempt at a Solution


I know that the angle ø, 0° < ø < 180°, that a line makes with the positive x-axis is called the angle of inclination of the line. However, I don't have any idea how to approach this question.
 
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Well your lines are in the xy-plane.
So why don't you draw the lines and find the angle using some trigonometry?

OR you can find the dot product with a unit vector in the direction of the x-axis <1,0>
 
rock.freak667 said:
Well your lines are in the xy-plane.
So why don't you draw the lines and find the angle using some trigonometry?

OR you can find the dot product with a unit vector in the direction of the x-axis <1,0>

How do find the solution without having to draw the lines?
 
Cuisine123 said:
How do find the solution without having to draw the lines?

the dot product of the direction of the vector line and the unit vector in the direction of the x-axis will give you the angle.
 

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