This document discusses using integration to find the area under a curve. It defines integration as the reverse of differentiation and shows how to find antiderivatives. It provides examples of indefinite and definite integrals, and explains how definite integrals between limits can be used to calculate the area under a curve over an interval. The document demonstrates this by finding the area under various curves bounded between given x-values. It also discusses how to handle areas below or partly above and below the x-axis.
INTRODUCTION
• INTEGRATION ISALSO CALLED ANTI-DIFFERENTIATION. THIS
MEANS THAT IT IS REVERSE DIFFERENTIATION.
• IF
𝒅𝒚
𝒅𝒙
= 𝒂𝒙 𝒏
THEN 𝒚 =
𝒂𝒙 𝒏+𝟏
𝒏+𝟏
, WHERE 𝒏 ≠ −𝟏.
DEFINITE INTEGRATION
• WHENWE ARE GIVEN VALUES LIKE THIS: 𝑎
𝑏
𝑓 𝑥 𝑑𝑥 , WHERE A AND B ARE THE
LIMITS OF THE INTEGRAL, THIS IS KNOWN AS DEFINITE INTEGRALS.
• EXAMPLE : −2
0
1 − 𝑡 − 𝑡2 𝑑𝑡
= 0 − [−2 −
−2 2
2
−
−2 3
3
]
=0 − −1
1
3
= 1
1
3
6.
USE
INTEGRATION
TO FIND AREA
THEAREA UNDER A GRAPH
CAN BE FOUND BY USING THE
FORMULA…
WHERE A IS THE LOWER LIMIT
AND B IS THE UPPER LIMIT.
7.
EXAMPLE
• FIND THEAREA UNDER THE CURVE 𝑦 = 𝑥2 + 2 IN WHICH THE AREA IS BOUNDED
BETWEEN X=2 AND X=6.