Thanks for doing that.

I agree with bobbym about having the y coords calculated for you. As the aim of this demo is to show the chord gradient approaching the limit as the points get closer, it should always be points on the curve, so you might as well force that. (If someone just wants to play with gradients of any points you already have a demo for that on the straight line page)

When there are many decimals places, the display gets messy and the slope box isn't large enough to show the final calculation.

For my screen shot I had y = sin(x) and A = (1.570796,1)

(i) Do you really need to put the slope value on the graph when it is shown in the box anyway?

(ii) Could you make the box larger and maybe have a round off limit so the display is always clear?

Thanks,

Bob

]]>Works for me! When I use the edit button it allows me to enter say (3,6). This is not on y = x^2. Could you make it that you only have enter the x value and the y value is computed automatically.

]]>Shows coords of points, has a calculation box down below, and allows for setting coords of points using "edit" button.

Waddya think?

]]>That's brilliant and you have done it so quickly!!

I would like to be able to specify the (x,y) coordinates and 'lock them in' for the duration of the interaction.

eg. Say I want the gradient at (1,1) on y = x^2.

Point A becomes (1,1) at all zoom levels, and only B can be varied.

There would then need to be a 'change point A' button.

Secondly, could you have a 'display table' option so that the calculations can be seen. (see picture below)

I've shown a table with 3 lines of calculations but, for the page, I'm thinking a single line that changes as B is moved, would be best.

(and I've used dx only because I cannot make a 'delta' in Excel)

Many thanks,

Bob

]]>Can you provide an (x,y) pair for A and B?

]]>Here it is: Slope of a Function at a Point

What do you think guys? How about the explanation?

]]>Hi MathsIsFun;

Very well done. I always enjoyed the manipulations using Δx instead of the dry differentiation rules. That was for me the reason calculus was fun. I think you have passed that on to anyone reading your page.

Also, I liked the use of Sam and Alex telling a story. But next time do not make them so friendly. Purists ( Galileo society ) are not going to appreciate the equation d = 5t^2.

Let's see you differentiate sin^11(x) using the delta x operator.

]]>Thanks.

Bob

]]>Thank you for those wonderful suggestions, I will work on them.

]]>Did you see post #3 ?

Bob

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