Jack Omar wrote:In the link about derivatives it is shown that it is 0/0 but I should take a really small difference and then shrink it to 0 so it is the same as 0/0 ???
I don't get that part with shrinking to 0, which is pretty much the same as 0/0.Hi Jack Omar,
Careful -- taking the limit as something approaches 0 is not quite the same as 0/0! We're only interested in what happens as gets really close to 0, not what happens at 0. This is the key part.The question we want to answer is: how do we describe the 'slope' of a function at any given point on its graph? Well, as the pictures you've added show, we can
(a) Take the first point on the curve, find another point on the curve, then draw a straight line through them...
That gives an estimate of what the slope at a given point is. But it's not quite right -- and as you move the points closer together on your graph, that 'estimate' becomes more and more accurate. (Likewise, moving the points further apart makes that 'estimate' less accurate.) That's what taking the limit as approaches 0 is intending to achieve, i.e. what happens when you bring those two points really, really close together?
(b) ...then calculate the slope of the line you've just drawn.Post #1 wrote:I think I made a mistake in last equation but I don't know why.
Looks OK to me -- isn't the last line the same as the first one?
Post #3 wrote:No -- the division by is for the previous step. They are saying that:Second question isn't there an error in the result ? There is 2x + Δx, then it is devided by Δx, 2x÷Δx + Δx÷Δx then 2x÷Δx + 1 ? Shrinking it into Δx to 0 I get 2x÷0 + 1 ?
I saw that you asked some questions about integration as well -- but let me know if this makes sense first and then we can move on.
Hello
Thank you so much for the answer !
I do have problem still with understanding
andIn the link about derivatives it is shown that it is 0/0 but I should take a really small difference and then shrink it to 0 so it is the same as 0/0 ???
I don't get that part with shrinking to 0, which is pretty much the same as 0/0.
Hi Jack Omar,
Careful -- taking the limit as something approaches 0 is not quite the same as 0/0! We're only interested in what happens as gets really close to 0, not what happens at 0. This is the key part.The question we want to answer is: how do we describe the 'slope' of a function at any given point on its graph? Well, as the pictures you've added show, we can
(a) Take the first point on the curve, find another point on the curve, then draw a straight line through them...
(b) ...then calculate the slope of the line you've just drawn.
I think I made a mistake in last equation but I don't know why.
Looks OK to me -- isn't the last line the same as the first one?
Second question isn't there an error in the result ? There is 2x + Δx, then it is devided by Δx, 2x÷Δx + Δx÷Δx then 2x÷Δx + 1 ? Shrinking it into Δx to 0 I get 2x÷0 + 1 ?
I saw that you asked some questions about integration as well -- but let me know if this makes sense first and then we can move on.
]]>See the link(s):
I think you can get the requisite information.
]]>Hi Jack Omar,
The topic in the first post is ' I don't understand integrals (definite integrals and indefinite integr.)
Thats why is gave the links.
O okey
But is it possible to answer to my question I gave ? I am really uncertain about my answers.
Thanks alot !
]]>The topic in the first post is ' I don't understand integrals (definite integrals and indefinite integr.)
Thats why is gave the links.
]]>Hello
I've asked in my last post about derivatives.
What do you think of what I said in my last post about derivatives.
In the link about derivatives it is shown that it is 0/0 but I should take a really small difference and then shrink it to 0 so it is the same as 0/0 ???
I don't get that part with shrinking to 0, which is pretty much the same as 0/0.
And could you take a look at my calculations
Thanks alot
]]>Hope these links help!
]]>Thank you for the links, it was really helpful but I do have some questions.
I want to also say that english is not my native language so, I am really sorry if my post was really messy, and I want to apologize if I can be hard to talk with, because sometimes I tend to ask the same question again.
My question is relates to this picture :
And this picture :
It is said that there is no difference 0÷0. But in derivatives I take small a very small difference and then shrink it to zero. But if I shrink it to 0 then y is also 0 as I know ? So why does it work ?
Second question isn't there an error in the result ? There is 2x + Δx, then it is devided by Δx, 2x÷Δx + Δx÷Δx then 2x÷Δx + 1 ? Shrinking it into Δx to 0 I get 2x÷0 + 1 ?
I'll start later asking questions for integrals, but I wanted to start slowly if its not a problem.
Have a nice day guys
]]>Welcome to the forum!
See the links:
]]>I've heard that anti-derivative mean anything. Why ? Derivative means that it is a slope of a function and AntiDerivative means nothing ? I don't get it
Derivative has even a proof that to calculate derivative I have to use limit :
Like in the picture. So for example when I have f(x)=x2 and I have two points x1=3,x2=4.
Then :
I think I made a mistake in last equation but I don't know why.
But to the point, how do I prove that indefinite integrals is an inverse operation of derivative and to calculate it I must really reverse the derivative.
Last question about definite integrals I read this website : https://www.askamathematician.com/2011/04/q-why-is-the-integralantiderivative-the-area-under-a-function/
And I was a bit lost because to calculate the area I must take a derivative from a function that is already a derivative function. Like what ?
I tried to calculate it but I don't get it.
I don't get it why we use f'(c)*(B-A) = f(b)-f(a) is the area ? I've changed the equation for the derivative and now it doesn't have any sense because now what is this f'(c) in that equation ?
I've changed the equation so now I don't know what is this f'(c) in f'(c)*(B-A) = f(b)-f(a). Or even if I know then f(b)-f(a)÷(B-A) * (B-A) =f(b)-f(a) So f(b)-f(a) =f(b)-f(a) .
It doesn't have anysense also why integral of f'(c)*(B-A) = f(b)-f(a) is equal f(c)(B-A) = F(b)-F(a) why does (B-A) stays the same ? I know that the intervals doesn't have to be numbers it can be also different function.
I've read so many textbooks and websites and I still don't get it.
Help ;<
Overall I don't get it why if I want to calculate the area I must derivate a derivated function, does calculating the area I need only derivative ?
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