# [TRAC-4090] Integral visual bug

-Loco- shared this problem 9 years ago

Hi,

The following input colorizes the entire area above the x-axis.

But the area between graph and x-axis should be colored instead.

f(x) = x^4 - 5 x^2 - 4

IntegralBetween[ f , 0 x , 5 , -4 ]

or

Integral[ f , 5 , -4 ]

The calculated values are correct.

Cheers

Loco

GeoGebra: 4.2.54.0

Java: 1.6.0_43-32bit

OS: Windows 7 Ultimate 64bit

1

Hi,

The following input colorizes the entire area above the x-axis.

But the area between graph and x-axis should be colored instead.

f(x) = x^4 - 5 x^2 - 4

IntegralBetween[ f , 0 x , 5 , -4 ]

or

Integral[ f , 5 , -4 ]

The calculated values are correct.

Cheers

Loco

GeoGebra: 4.2.54.0

Java: 1.6.0_43-32bit

OS: Windows 7 Ultimate 64bit

hello

help of GG:

Gives the definite integral of the difference f(x) ‐ g(x) of two function f and g over the interval [a, b], where a is the first number and b the second, with respect to the main variable.

try IntegralBetween[ f , 0 x , -4 ,5 ]

saludos

1

Hi,

yes, I already knew this solution.

I wanted to report the visual bug.

Besides:

$\int^{a}_{b}f\left(x\right) \; \mathrm{d}x \neq \int^{b}_{a}f\left(x\right) \; \mathrm{d}x$

Cheers

Loco

1

hello

base=2 high=3 is a rectangle over xaxis

base =2 high=-3 is a rectangle under xaxis

but i think that base=-2 high=-3 is not a visual concept ( must be area=+6 over or under the xaxis?)

saludos

1

Hi mathmagic,

yes of course, all these rectangles include areas of 6 area-units.

But the value of the integral depends on the way you integrate (e.g. from right to left, from left to right, or multiplicated with -1).

Nevertheless the values are not my problem!

GeoGebra accepts the input of values where a > b (this is not an error) and colorizes sometimes the wrong sections.

Cheers

Loco

1

Error / Bug still present in:

GeoGebra 4.4.5.0 (22 December 2013)

Java: 1.7.0_40

OS: Windows 8

Architecture: x86 / x86

1