Perplex
Dashboard
Topics
Exponents & LogarithmsApproximations & ErrorSequences & SeriesFinancial Mathematics
Cartesian plane & linesFunction TheoryModelling
2D & 3D GeometryVoronoi Diagrams
ProbabilityDescriptive StatisticsBivariate StatisticsDistributions & Random VariablesInference & Hypotheses
DifferentiationIntegration
Review VideosFormula BookletMy Progress
BlogLanding Page
Sign UpLogin
Perplex
Perplex
Dashboard
Topics
Exponents & LogarithmsApproximations & ErrorSequences & SeriesFinancial Mathematics
Cartesian plane & linesFunction TheoryModelling
2D & 3D GeometryVoronoi Diagrams
ProbabilityDescriptive StatisticsBivariate StatisticsDistributions & Random VariablesInference & Hypotheses
DifferentiationIntegration
Review VideosFormula BookletMy Progress
BlogLanding Page
Sign UpLogin
Perplex
IB Math AISL
/
Integration
/
Skills
Edit

Skill Checklist

Track your progress across all skills in your objective. Mark your confidence level and identify areas to focus on.

Track your progress:

Don't know

Working on it

Confident

📖 = included in formula booklet • 🚫 = not in formula booklet

Track your progress:

Don't know

Working on it

Confident

📖 = included in formula booklet • 🚫 = not in formula booklet

IB Math AISL
/
Integration
/
Skills
Edit

Skill Checklist

Track your progress across all skills in your objective. Mark your confidence level and identify areas to focus on.

Track your progress:

Don't know

Working on it

Confident

📖 = included in formula booklet • 🚫 = not in formula booklet

Track your progress:

Don't know

Working on it

Confident

📖 = included in formula booklet • 🚫 = not in formula booklet

Skill Checklist

Track your progress across all skills in your objective. Mark your confidence level and identify areas to focus on.

10 Skills Available

Track your progress:

Don't know

Working on it

Confident

📖 = included in formula booklet • 🚫 = not in formula booklet

Track your progress:

Don't know

Working on it

Confident

📖 = included in formula booklet • 🚫 = not in formula booklet

Definite Integrals, Areas, and Basic Anti-Derivatives

10 skills
Area under a curve
SL 5.5

The area between a curve ​f(x)>0​ and the ​x​-axis is given by

​
A=∫ab​f(x)dx📖
​
Trapezoidal Rule
SL AI 5.8

Approximate area beneath a curve from ​x=a​ to ​x=b​ by summing the area of ​n​ trapezoids of equivalent width.


Each trapezoid's area is the common width ​(nb−a​)​ times the average of the function's value on the left and rigth side of the trapezoid:

Integration as reverse differentiation
SL 5.5

Integration, or anti-differentiation, is essentially the opposite of differentiation. We use the integral symbol​∫​ and write:

​
∫f(x)dx=a function with a derivative off(x)
​

By convention we denote this function ​F:

​
∫f(x)dx=F(x)🚫
​

We can also write

​
∫dxdy​dx=y🚫
​

Notice the ​dx​ under the integral. This tells us which variable we are integrating with respect to - in this case we are reversing ​dxd​.

The Integration Constant
SL 5.5

Since the derivative of a constant is always zero, then if if ​F′(x)=f(x), then ​(F(x)+C)′=f(x).


This means that when we integrate, we can add any constant to our result, since differentiating makes this constant irrelevant:

​
∫f(x)dx=F(x)+C🚫
​
Anti-Derivative of xⁿ, n∈ℤ
SL 5.5
​
∫xndx=n+1xn+1​+C,n∈Z,n=−1📖
​
Integrals of sums and scalar products
SL 5.5

In the same way that constant multiples can pass through the derivative, they can pass through the integral:

​
∫af(x)dx=a∫f(x)dx🚫
​

And in the same way that the derivative of a sum is the sum of the derivatives:

​
∫f(x)+g(x)dx=∫f(x)dx+∫g(x)dx🚫
​
Boundary Conditions
SL 5.5

If we know the value of ​y​ or ​f(x)​ for a given ​x, we can determine ​C​ by plugging in ​x​ and ​y.

Definite Integrals
SL 5.5

A definite integral is evaluated between a lower and upper bound.

​
∫ab​f(x)dx is the integral of f(x)dx from x=a to x=b
​

We can solve a definite integral with

​
∫ab​f(x)dx=[F(x)]ab​=F(b)−F(a)🚫
​


where ​F(x)=∫f(x)dx.

Calculating Definite Integral with GDC
SL 5.5

Graphing calculators can be used to evaluate definite integrals.


For example, on a TI-84, math > 9:fnInt(, which prompts you with ​∫□□​(□)d□. Make sure the variable of your function matches the variable that you take the integral with respect to.

Definite Integral Rules
SL 5.5

Integrals of the same function with adjacent domains can be merged:

​
∫ab​f(x)dx+∫bc​f(x)dx=∫ac​f(x)dx🚫
​

Similarly, the domain of an integral can be split:

​
∫ab​f(x)dx=∫am​f(x)dx+∫mb​f(x)dx🚫
​

for any ​a<m<b.

Skill Checklist

Track your progress across all skills in your objective. Mark your confidence level and identify areas to focus on.

10 Skills Available

Track your progress:

Don't know

Working on it

Confident

📖 = included in formula booklet • 🚫 = not in formula booklet

Track your progress:

Don't know

Working on it

Confident

📖 = included in formula booklet • 🚫 = not in formula booklet

Definite Integrals, Areas, and Basic Anti-Derivatives

10 skills
Area under a curve
SL 5.5

The area between a curve ​f(x)>0​ and the ​x​-axis is given by

​
A=∫ab​f(x)dx📖
​
Trapezoidal Rule
SL AI 5.8

Approximate area beneath a curve from ​x=a​ to ​x=b​ by summing the area of ​n​ trapezoids of equivalent width.


Each trapezoid's area is the common width ​(nb−a​)​ times the average of the function's value on the left and rigth side of the trapezoid:

Integration as reverse differentiation
SL 5.5

Integration, or anti-differentiation, is essentially the opposite of differentiation. We use the integral symbol​∫​ and write:

​
∫f(x)dx=a function with a derivative off(x)
​

By convention we denote this function ​F:

​
∫f(x)dx=F(x)🚫
​

We can also write

​
∫dxdy​dx=y🚫
​

Notice the ​dx​ under the integral. This tells us which variable we are integrating with respect to - in this case we are reversing ​dxd​.

The Integration Constant
SL 5.5

Since the derivative of a constant is always zero, then if if ​F′(x)=f(x), then ​(F(x)+C)′=f(x).


This means that when we integrate, we can add any constant to our result, since differentiating makes this constant irrelevant:

​
∫f(x)dx=F(x)+C🚫
​
Anti-Derivative of xⁿ, n∈ℤ
SL 5.5
​
∫xndx=n+1xn+1​+C,n∈Z,n=−1📖
​
Integrals of sums and scalar products
SL 5.5

In the same way that constant multiples can pass through the derivative, they can pass through the integral:

​
∫af(x)dx=a∫f(x)dx🚫
​

And in the same way that the derivative of a sum is the sum of the derivatives:

​
∫f(x)+g(x)dx=∫f(x)dx+∫g(x)dx🚫
​
Boundary Conditions
SL 5.5

If we know the value of ​y​ or ​f(x)​ for a given ​x, we can determine ​C​ by plugging in ​x​ and ​y.

Definite Integrals
SL 5.5

A definite integral is evaluated between a lower and upper bound.

​
∫ab​f(x)dx is the integral of f(x)dx from x=a to x=b
​

We can solve a definite integral with

​
∫ab​f(x)dx=[F(x)]ab​=F(b)−F(a)🚫
​


where ​F(x)=∫f(x)dx.

Calculating Definite Integral with GDC
SL 5.5

Graphing calculators can be used to evaluate definite integrals.


For example, on a TI-84, math > 9:fnInt(, which prompts you with ​∫□□​(□)d□. Make sure the variable of your function matches the variable that you take the integral with respect to.

Definite Integral Rules
SL 5.5

Integrals of the same function with adjacent domains can be merged:

​
∫ab​f(x)dx+∫bc​f(x)dx=∫ac​f(x)dx🚫
​

Similarly, the domain of an integral can be split:

​
∫ab​f(x)dx=∫am​f(x)dx+∫mb​f(x)dx🚫
​

for any ​a<m<b.