Download Mathematics Calculus Integrals and more Lecture notes Mathematics in PDF only on Docsity! MATH-141 Lecture Notes
04.01.2023
TOTAL AREA
To find the. orea between the graph of y= fC and
the. X-axts over the. interval “Caib]:
1) Subdivide Lob) at the zeros of f-
2) Tritegrate. £ over Gach subinterval
3) Add the absolute values of the jntegrals
Ex: Lek fl O= x4 and GOO = GH. For each furchon
Compute :
a) the de fiatte. rategral over the intewol (22).
b) the area between the. goph and X-axis qver ([-2/2J.
2 2 2
z 7x am 2)4yn [Xo_
a) [& 4 dx = [a4 ‘I {4c dds [4 ad
ra ~ 32 + = 32
— 3
b) The area is = square units in beth cases:
The de finite integral af fC) is neg etive » but the are
is positive . Beocouse orea always @ Nonnegective
quantity
Ex: ket fld= Sinx between X=O and %= QI Compute:
a) the de. finite integral of $e) over Coan] .
b) the. ore between the graph 2 f£ f (X) and the x-OKxI's
over Coa)
Ys Siax
a
T 2
a) 5 Siax dx = —-@sx
5
=- Cos2ti+ Gs O
~-144
= O
1
L) f Sia xdxy = -Cosx
o
°
= -CosT+ (Cos 0)
TT
~-C4)+ 4 Result:
= 2 The total area
qr i> the sum of
| Siaxd x= - COSX ay The. ak solute
values of tno
y T intog cols
= -—Cos 27+ Cost
=a -4-4 Avene |2)/+|-2]=4
+ +2
Since. Areas JAl+]/Al
Ex! feeder f
= Siax dx
Cas x
£ (-#
d
- ~dnfulte
~dn | Cosx|ee
= dn |Secx|+ ce
ax 9
. ae!
e*+e™
ax
it
[ Secxde = 7
u=Cos X
du aVink dx
Note: ~ tnt = dn J
We Set) us e*
duse™. dx
Are ton ute
Arc tan (e%)4 Cc
Multiply and divide by (Sec x +Tanx.)
= [Secx (Secx4 Tanx) dy
Gecx +Tank
+f Spel Sex Tonk Sec*x + Secx Tanx dy
Secx+ Seext Tanx
du
Us &e x+ Tanx
dlu=(Secx Tank+ Sct) dx
=Anlulec = Lal Secx+Tanx| +o
SUMMARY
J tans An| Sec x| 4c
J ot wdx= An | Sinx| to
[ See x dx = Ln| Secxstanx | 4.0
[Case xde= = An | Cosec x+ Cotxl+c
5.6. Dernite INTEGRAL SUBSTITUTIONS cind
THe AREA BeTuweeN Cueves
THEOREM: Substitution in Definite Integ ral .
Tf 9! is continuous on the interval Cab) ond Ff Is
ContinuasS on the range. of gH) =u, than
| glh?
J £ (909]- g'oadx = { Ff (a) du
~ glo)
4
Z£XM: Jf 3x? (xt44 dx= ?
1
We Set | ue aL when x42-4 ., U4 =(-1),.1= 0
du= 3x* dx When Xz1= 4 u,2 44-2.
a ou,
= Yooa 2 a/z ~ ce
T= J Jo.du = 20 |" = 2f gto) = 48
oO
tt/z
xf Qte Cs'Bdo~7
It/y
Lowy
Ve Set us Cot &
du=~Csct @d&
Oo
t= ( uide)= “4 ]°
AIL
1
= o+4
2
= ot
2
T.way
=Csc 8
4=- Csc8. Cor OB
Le ~lu.du = - 7
2 2
~ csc 9
2
Te — ese 8 |
TA
Definite Integrals o £ Symmetric Functions
THEOREM! het oa be continuous on +he Symmetric ite vrenl. Ca, a).
= q Q
o) If fis even , then { forde= 2. f $xadx
= °
b) LL fii add > then PP p00 dx = 9
If fis even funetion
the integral form -a tea
is twice the ixtegral
fare Oo tao.
rf L is an_odd function
the tecteg ral fron -a toa
equals O..
Integration Ys ith respect +o y
7
L a region bounding Curves Gre described b
unetionS of y 5 the bosic ferrmalor has y in place of x.
3
A= ‘ fF (y)-9 ly) Joy
f(y) : right-hand Curve.
F(y)- Cy) is nonnegative.
3 Cy) -Aett-hand curve-
ZS: Find the area of the region in the. pest quadrant
that js bounded abe by y =VK dnd below by the
X-oxis Q@nd the Vue yer-2. /
- jek yax = X="
Ui Yo Rod Kaa?
Z5 night curve
rer
a = | right X tee) ty
A= {em -(r)-¢
~ 40
Pres 55
Ole) Finol Exar. Questions
i) Ee ax =?
TT é
Us dink t= ftanu -du
dus
fee du t=Cosy
Cosu adb= -Sinudy
- (de
Js
= -dnltl te
~ = dn { Cos(loa) J 4c
x = 7
2) f 1d
© Y Gee a
* _2/2
We Seta ys ctf r{ U_. clu
1
= 3. ue |"
= 3(i2- ‘)
2) f ton*xdx =?
— u= Cosy
= Sr dx du=- Sinxdk
Cos? Xx
Sin x= Siar dx SintX = 1 COR? x
Cos? x ars tu
(-u) Cu) iF
“TGs — du [de We 2% dnlul+c
+lalGos Kee
Heer ?
fh 4 Sin? x Cost el x Si ax= 1st
f[ = (2 Sinx.Cosx)™ +
= Sin 2X
~ 1 [ff t-los4k gy fe
af 2 [Sic = test
a
- [x Sax Je eae
g L Cas? —Sjiax = Cos 2x
Gs Int) ~Sin"X = Cos2x
ime ak = Bgintx
a
Basic + “
substitutim|oyartt dy #)
Fule xe
_ 7=dx a\ +S
du { LT -|- u aL du
= du 4 =dX —S
4 Ve set:
u(qurdu | t= 4-u"
clt= -gudu