# Making a definite integral equal and indefinite integral?

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)

andrewkirk
Homework Helper
Gold Member
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)##.

• Saracen Rue
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?

andrewkirk
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