Introduction to the coordinate plane | Introduction to algebra | Algebra I | Khan Academy

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Rene Descartes, known for his quote "I think, therefore I am," also connected algebra and geometry through Cartesian coordinates, allowing visual representation of equations like y = 2x - 1 on a graph. Descartes associated x with the horizontal axis and y with the vertical axis, pioneering the concept of plotting points to understand relationships between variables and how linear equations form lines on a graph.

Insights

  • Descartes, known for his famous quote "I think, therefore I am," not only contributed to philosophy but also revolutionized algebra by connecting it with geometry through Cartesian coordinates, allowing for the visualization of equations.
  • Through his association of x and y with the horizontal and vertical axes respectively, Descartes established a fundamental convention for plotting points and understanding relationships between variables, paving the way for the graphical representation of mathematical concepts and the bridging of algebra and geometry.

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Recent questions

  • Who was a contemporary of Galileo?

    Rene Descartes

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Summary

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Descartes: Linking Algebra and Geometry Through Coordinates

  • Rene Descartes, a renowned figure in math and philosophy, was a contemporary of Galileo, albeit much younger, dying at 54 compared to Galileo's old age.
  • Descartes is famous for the philosophical quote "I think, therefore I am," but also shared practical advice on perseverance, stating, "You just keep pushing."
  • Descartes is crucial to algebra as he linked algebra and geometry, showing how equations like y = 2x - 1 can be visualized and understood through Cartesian coordinates.
  • In algebra, symbols like y and x represent values in equations, allowing for the establishment of relationships and the visualization of these relationships on a coordinate plane.
  • Descartes associated x with the horizontal axis and y with the vertical axis, creating a convention for plotting points and understanding relationships between variables.
  • Cartesian coordinates, named after Descartes, are used to represent points on a two-dimensional plane, with x and y values indicating positions along the axes.
  • By plotting points based on x and y values from equations, Descartes showed how linear equations form lines on a graph, bridging algebra and geometry.
  • Linear equations, like y = 2x - 1, appear as lines when graphed due to the relationship between x and y values, a concept Descartes pioneered.
  • Descartes' work laid the foundation for understanding how equations can be visualized and how different types of equations lead to various shapes on a graph.
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