INTEGRATION

NB: You have to do something about a product or a fraction.
Either they are in the tables or you let u = one part and du = (the rest)dx.

 

POWERS OF X

NB. ,  etc.  Note that this rule does not apply to integrating .

 

Questions: 2005 I 8a(i), 2004 I 8a(i), 2003 I 8a (i), 2002 I 8a, 2001 I 8a (i), 2000 I 8a (i), 1999 I 8a, 1998 I 8a, 1996 I 8a (i), 1995 I 8a (i), 1994 I 8a.

 

SIMPLE SUBSTITUTIONS

(a) . Let u = ax  and du = adx   (i.e. .)

 

Questions: 2005 I 8a(ii), 2004 I 8a(ii), 2003 I 8a (ii), 2003 I 8c (i), 2001 I 8a (ii), 2000 I 8a (ii), 1997 I 8a (i), 1996 I 8a (ii), 1994 I 8a.

 

(b) . Let  and

 

Questions: 1999 I 8b (ii),

 

EASY PRODUCTS

e.g.         just square out the bracket
e.g.

 

Questions 1998 I 8b (ii), 1997 I 8a (ii), 1996 I 8a(ii)

 

EASY FRACTIONS

(a) e.g.  just divide by the denominator to get

(b) e.g. . Let  and

 

Harder Questions: 1997 I 8c, 1995 I 8c (ii), 1994 I 8c (i) first integral, 1994 I 8c (ii).

 

(c) e.g. . Let , , and .
Then square out the numerator and divide by the denominator.

 

Questions: 1997 I 8b (ii)

 

FRACTIONS WITH A QUADRATIC IN THE DENOMINATOR.

(a)        or                   let

Note: n can be a two, three, or a half etc.

 

Questions: 2005 I 8b(i), 2003 I 8b (i), 2002 I 8b(i), 2001 I 8b (ii), 2000 I 8b (ii), 1998 I 8b (i),

Harder Questions: 1996 I 8c (i)

 

(b)       or                  complete square for inverse tan /sin

 

Questions: 2004 I 8c(i), 2004 I 8b(i), 2002 I 8b (ii), 2001 I 8b (i), 2000 I 8c (i), 1995 I 8c (i), 1994 I 8c (i) first integral.

 

TRIGONOMETRIC INTEGRALS.

(a) Change a product to a sum using page 9 of the tables.

 

(b)  and so on. This is a special case of (a). Use the formulae on page 9.

 

Questions: 2005 I 8b(ii), 2000 I 8b (i), 1999 I 8b (i), 1997 I 8b (i), 1996 I 8b (ii), 1995 I 8c (i)

 

(c) . Let
or . Let .

 

Questions: 2004 I 8b(ii), 2003 I 8b (ii),

 

AREA BETWEEN A CURVE AND A LINE

 

Questions: 2004 I 8c, 2002 I 8c, 2001 I 8c, 2000 I 8c (ii), 1998 I 8c, 1996 I 8c (ii), 1995 I 8b, 1994 I 8a.

 


AREA OF A CIRCLE

e.g.

Note: This is a rearrangement of , i.e. a circle of centre (0, 0) and radius 2.
The integral is the area of one quarter of the circle.
Use the double substitution  and  and change the resulting product to a sum using page 9 of the Tables.

 

Questions 1999 I 8c, 1996 I 8b (i),

 

VOLUMES OF ROTATION

For a curve rotated about the x-axis:


For a curve rotated about the y-axis:

Questions: 2005 I 8c(ii), 2003 I 8c (ii), 1995 I 8c (ii)