Making a definite integral equal and indefinite integral?

  • #1
144
7
I have a calculator which allows me to sketch indefinite integrals - it assumes c = 0. However, when I try to use Desmos Online Graphing Calculator, it won't let me do this with it's integral function. It keeps trying to make me use definite integrals.

I know that ∫(a,b,f(x)dx = F(a) - F(b), so I was wondering if it's possible to define a and b so that the resulting definite integral equals the indefinite integral (where c = 0)
 

Answers and Replies

  • #2
andrewkirk
Science Advisor
Homework Helper
Insights Author
Gold Member
3,886
1,454
How does it sketch the definite integrals? If it sketches the curve of ##F(x)## vs ##x## where ##F(x)## is defined as:
$$F(x)=\int_a^x f(t)dt$$
then the sketch will be exactly the same as that of an indefinite integral ##G=\int f(x)dx## with zero integration constant, except shifted downwards by ##G(a)##.
 
  • Like
Likes Saracen Rue
  • #3
144
7
How does it sketch the definite integrals? If it sketches the curve of ##F(x)## vs ##x## where ##F(x)## is defined as:
$$F(x)=\int_a^x f(t)dt$$
then the sketch will be exactly the same as that of an indefinite integral ##G=\int f(x)dx## with zero integration constant, except shifted downwards by ##G(a)##.
So if I make a equal to a x-intercept of the indefinite integral of f(x), then
$$F(x)=\int_a^x f(t)dt$$
With no shift?
 
  • #4
andrewkirk
Science Advisor
Homework Helper
Insights Author
Gold Member
3,886
1,454
Yes, that should work.
 
  • Like
Likes Saracen Rue
  • #5
144
7

Related Threads on Making a definite integral equal and indefinite integral?

Replies
9
Views
962
Replies
11
Views
1K
Replies
10
Views
955
Replies
12
Views
6K
Replies
11
Views
28K
  • Last Post
Replies
1
Views
1K
  • Last Post
Replies
6
Views
863
  • Last Post
Replies
2
Views
2K
  • Last Post
Replies
1
Views
1K
Top