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Introduction to Calculus and Lines

Sep 23, 2024

Calculus Lecture Notes

Introduction

  • Official start of Calculus class.
  • Focus on reviewing Math 2 concepts and basic algebra needed for success in calculus.

Section 0.1: Lines

Key Concepts

  • Definition of Lines: Infinite points, require two points to define a line.
  • Graphing a Line: Need two points or a point and a slope.
  • Slope: Represents how a line rises or falls.
    • Formula: ( m = \frac{y_2 - y_1}{x_2 - x_1} )
    • Derived from choosing two points ((x_1, y_1)) and ((x_2, y_2)).

Deriving the Slope Formula

  • Use coordinates ((x_1, y_1)) and ((x_2, y_2)) for generality.
    • Rise: ( y_2 - y_1 )
    • Run: ( x_2 - x_1 )
  • Slope ( m = \frac{\text{rise}}{\text{run}} = \frac{y_2 - y_1}{x_2 - x_1} )

Point-Slope Form

  • Fix one point to derive point-slope form.
    • Equation: ( y - y_1 = m(x - x_1) )
  • Allows plug-and-play for ( x ) to solve for ( y ).

Graphing Lines

Using Point-Slope and Slope-Intercept

  • Example: Given two points, find slope and apply point-slope form.
  • Convert to slope-intercept form for easy graphing: ( y = mx + b )

Horizontal and Vertical Lines

  • Horizontal Line: ( y = c ), crosses the y-axis.
  • Vertical Line: ( x = c ), crosses the x-axis.

Parallel and Perpendicular Lines

Parallel Lines

  • Have the same slope.
  • Example: Finding an equation parallel to a given line.

Perpendicular Lines

  • Slopes are negative reciprocals of each other.
  • Example: Finding an equation perpendicular to a given line.

Angle of Inclination

  • Angle a line makes with the x-axis.
  • Relation with Slope: ( \tan(\theta) = \text{slope} )
    • Example: Given angle, find slope using tangent.
    • Reverse: Given slope, find angle using inverse tangent.

Distance Formula

  • Derived using the Pythagorean theorem.
  • Formula: ( d = \sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2} )
  • Used to calculate distance between two points.

Conclusion

  • Emphasis on understanding algebra and trigonometry foundations for calculus success.
  • Upcoming topics include derivatives and integrals involving trig functions.