How to sketch this? (1 Viewer)

rsingh

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Hey guys,

How do you sketch this fn?

y = x - 3logx, including stationary pt(s).

I'm not sure how to graph these functions, where you have "one fn" plus/minues "another function".

like for example, in this case, the one fn is "x" and the other fn is "3logx".

also, if anyone knows, i think this may be more of a 3u thing .. i do 3u, so help from you guys would be helpful here..
how do you graph fns like "xe^2x" and stuff like that, where oone function is multiplied/divided by another?

Any help would be highly appreciated!
Thanks.
 

Dreamerish*~

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Find where the graph crosses the x and y-axes by substituting y = 0 and x = 0 into the equation.

Derive the equation and use d/dx = 0 to find stationary points, then use the second derivative to determine whether they are maximum or minimum points.
 

acmilan

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The easiest method would be something taught in 4 unit, where you sketch the graphs of those two functions separately, and then add the ordinates. Simlarly for the ones where you divide or multiply.

There are a number of things you need to consider: all that Dreamerish*~ said, including the consideration of assymptotes and limits.

I'd say all the functions you described in your post are a little beyond 2 unit maths and perhaps even 3 unit, unless they somehow help you out in sketching the graphs.
 
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Jago

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or superposition as it's called in physics :p
 

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