Help with graphing y=x f(x) (1 Viewer)

[Lucas Shine]

People say you need to get a feel for scetching y=x f(x). I was just wondering if you guys would be so kind as to helping me on my way. A step by step guide or just a tip would be much appreciated.

Thanx in Advance

 

[Tofuu]

sketch x and then f(x), then multiply ordinates?
when people say 'you need to get a feel' this is kind of true(achieved by sketching quite a few graphs)

 

[Lucas Shine]

sketch x and then f(x), then multiply ordinates?
when people say 'you need to get a feel' this is kind of true(achieved by sketching quite a few graphs)

When you say, multiply the ordinates, what exactly do you mean?

 

[Lukybear]

Like times each pt together

Say at y=x, x=1, y=1, and at y=f(x), x=1, y=5

then y=xf(x), at x=1 y =5 (1x5)

 

[biopia]

When x = 0, f(x) obv = 0
When x = 1, f(x) = f(x). That is, it will remain that same. Also for -1. I am sure you know this too.

Beyond that though, f(x) will be multiplied by higher and higher numbers so it looks like basically the same graph, except much more spread out on the y axis.

Think of ordinates as points also, so your multiplying the points on each of the respective graphs.

 

[The Nomad]

For these things, I would suggest just finding the stationary points (even approximately) and intercepts, then draw the general shape.

If the curve is a polynomial, all that's needed is to add an intercept at x = 0 .

 

[Lucas Shine]

Thanks Guys. I think I understand it now and I'm starting to get a feel for it (with a few hours practice). I still struggle a bit with the very complicated ones, as is probably to be expected.

 

[gurmies]

These ones are awful. Absolutely cannot stand them.

 

[Tofuu]

When you say, multiply the ordinates, what exactly do you mean?

abscissa= x values on number plane

ordinates= y values on number plane