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dnvu
Jun21-04, 03:54 PM
HI, please lend me some hints on how to graph the following equation in terms of y.

x = y + sin[y]

I know to plot it in terms of y, i should simply switch the places of y's and x's:

y = x + sin[x]

but i don't know how it looks like on the graph. Any idea how?

Appreciate it!

e(ho0n3
Jun21-04, 04:37 PM
There are two ways to figure out what the graph looks like: (1) Get some graphing software and have it do it for you (2) or do it yourself. If you will do it yourself, I suggest you first draw a table of values (one column for the independent variable(s) and another for the dependent variable). After that, just plot the values in cartesian space.

The graph of x = y + sin y looks like the graph of x = y except that instead of having a straight line, you have a sinosoudial (is that spelled right?) one.

cookiemonster
Jun21-04, 04:47 PM
Alternatively, for the graph of a sum of two functions, you could plot each individually and then kind of eyeball add them. For instance, your example

f(y) = y + sin(y)

Notice that f(y) is the sum of two functions, i.e. y and sin(y).

So you'd plot g(y) = y and h(y) = sin(y). Then you'd add them by thinking that the length between the horizontal axis and h(y) should be added to the length between the horizontal axis and g(y).

cookiemonster

JonF
Jun21-04, 05:46 PM
Or you could find the first and second derivative, use the first for increasing vs. decreasing and the second for concavity.

HallsofIvy
Jun21-04, 10:42 PM
I know what it means to "graph a function". What do you mean by "graph in terms of y"?