Q 31 :    

The area of the region {(x,y):x2+4x+2y|x+2|} is equal to         [2025]

  • 5

     

  • 7

     

  • 24/5

     

  • 20/3

     

(4)

We have, x2+4x+2y|x+2|

 (x+2)22y|x+2|

   Required area =42|(x2)(x+2)2+2|dx+20|(x+2)(x+2)2+2|dx

=42|x(x+2)2|dx+20|x(x+2)2+4|dx

=[|x22(x+2)33|]42+[|x22(x+2)33+4x|]20

=103+103=203.



Q 32 :    

The area of the region enclosed by the curves y=exy=|ex1| and y-axis is:          [2025]

  • loge2

     

  • 1loge2

     

  • 2loge21

     

  • 1+loge2

     

(2)

Given: Region is bounded by curves y=ex and y=|ex1|.

The graph is given by

When ex=|ex1|

 ex=ex+1                              [ex-1<0]

 2ex=1  ex=1/2  x=ln(2)

Now, area is given by.

A=ln(2)0[ex(1ex)]dx=ln(2)0(2ex1)dx

=(2exx)ln(2)0=21ln(2)=1ln(2).



Q 33 :    

The area of the region {(x,y):0y2|x|+1, 0yx2+1, |x|3} is         [2025]

  • 173

     

  • 323

     

  • 643

     

  • 803

     

(3)

Given, the area of region

{(x,y):0y2|x|+1, 0yx2+1, |x|3}

   Required area =202(x2+1)dx+23(2x+1)dx

                                    =2[(x33+x)02+(2x22+x)23]

                                    =2[83+2]+2(6)

                                    =2[143]+12

=643 sq. units.



Q 34 :    

The area of the region bounded by the curves x(1+y2)=1 and y2=2x is :         [2025]

  • 2(π213)

     

  • π413

     

  • π213

     

  • 12(π213)

     

(3)

We have, x(1+y2)=1         ... (i)

and y2=2x          ... (ii)

From equation (i) and (ii), we get

x(1+2x)=1 2x2+x1=0

 x=12, x=1          (Reject)

From (ii), y2=2(12)  y=±1

   Required area =11(11+y2y22)dy

                                   =(tan1y-y36)|11=π2-13.



Q 35 :    

Let the area of the region {(x,y):2yx2+3, y+|x|3, y|x1|} be A. Then 6A is equal to :           [2025]

  • 14

     

  • 16

     

  • 18

     

  • 12

     

(1)

Required area, A = Rectangle ABDE – Area of region EDC

 A=4201((3x)(x2+32))dx

 A=42{3xx22x3632x}01

 A=42{3121632}=73

So, 6A = 14.



Q 36 :    

Let the area enclosed between the curves |y|=1x2 and x2+y2=1 be α. If 9α=βπ+γ; β, γ are integers, then the value of |βγ| equals           [2025]

  • 27

     

  • 15

     

  • 33

     

  • 18

     

(3)

We have, c1 : |y|=1x2 and c2 : x2+y2=1

   Required area =α=4[(Area of circle in1st quadrant)01(1x2)dx]

=4[(π(1)4)[xx33]01]

=4[π4(113)]=4[π423]

=π83

Hence, 9α=9π24

On comparing with 9α=βπ+γ, we get β=9 and γ=24

  |βγ|=|9(24)|=33.



Q 37 :    

If the area of the region {(x,y):|4x2|yx2, y4, x0} is (802αβ), α, βN, then α+β is equal to _________.          [2025]



(22)

Required area =22(x2(4x2))dx+(222)×4222(x24)dx

=[2x334x]22+828[x334x]222

=402316=80266

 α=6, β=16

 α+β=22.



Q 38 :    

The area of the region bounded by the curve y = max {|x|,x|x2|}, the x-axis and the lines x = –2 and x = 4 is equal to _________.          [2025]



(12)

Required Area = Area of OAB + Area of region OCDEO

=12×2×2+01(2xx2)dx+13xdx+34(x22x)dx

=2+23+4+163

= 12 sq. units.



Q 39 :    

If the area of the region {(x,y):|x5|y4x} is A, then 3A is equal to __________.          [2025]



(368)

Area A=1254xdx12×4×412×20×20

                =[4x3/2×23]125208

                =83(1251)208

                =3683 sq. units

 3A=368.



Q 40 :    

Let the area of the bounded region {(x,y):09xy2, y3x6} be A. Then 6A is equal to __________.          [2025]



(15)

We have,  09xy2, y3x6

Required area = A=|03y29dy+36(y+63)dy|

                                  =|19[y33]03+13(y22+6y)36|

                                  =|19[90]+13[183692+18]|

                                  =|1+13[92]|

                                  =|132|=|52|=52 sq. units

  6A=6×52=15