1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Graphing a function V.S. another function

  1. Jun 20, 2011 #1
    1. The problem statement, all variables and given/known data

    Hi,

    I'm really use to graphing a function vs x, were the x axis would be the input to the function and the output would be the vertical function, were at each point on the graph would be the output evaluated at that particular x value

    So I'm learning how to use MATLAB for my degree and the below is a exercise from my book

    x_x(t) = t V_0 cos(theta)
    x_y(t) = t V_0 sin(theta) + (a t^2)/2

    were
    x_x(t) = horizontal displacement of a projectile as a function of time in
    x_y(t) = vertical displacement of a projectile as a function of time
    t = 0:.01:20 s (all the values that occur by increments of .01 from 0 to 20)
    theta = pi/4
    a = -9.8 m/s^2

    the particular exercise had me plotting x_y(t) V.S. x_x(t) on a graph, this is when I realized I had never done such a thing before were the x axis is not the input and the y axis is the output of some function evaluated at that particular x value... So I was wondering what exactly is the meaning of this graph, it's the vertical displacement that occurs at a particular horizontal displacement? Sense there evaluated at the same time values? but I was wondering if there was any way to come up with the function that describes the plot?

    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Jun 21, 2011 #2
    These are called parametric equations.

    Square both equations. Then add them. Simplify using the pythagorean identity. Try to recognize the resulting single equations as a circle = something.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Graphing a function V.S. another function
  1. Graphing a function (Replies: 1)

  2. Graphing a function (Replies: 3)

Loading...