Thursday, 18 December 2014

8.Mallapragada's. Mathematics (Square roots and cube roots)



 (Square roots and cube roots)

Sl. No.
                /Problems
Answers
1.
Evaluate  root of 6084 by fraction method

2.
Find the square root of  1471369  

3.
Evaluate  :root 248 +root 51 +root 169=

4.
What is the square root of 0.0009?

5.
Fiend the value of root 1 to the power of 9/16

6.
Find the value of 3 up to three places of decimal

7.
   root 176 + root 2401=?

8.
Square  root ate of 225/729 – Square rout  of 25/144 + square rout of 16/81 ?

9
Square Root of  (a+2)(b+3)/c + 1 if a=6 b=15, c= 3 find the value?

10
(86.49)1/2 + {(5+x)2}1/2 = 12.3  find x

11
X + y+root xy   If x = 6, y= 24 find ?

12
If y= 10 then what is the value of 10y  root y3 – y2 = ?

13
52/x =     (169/289)1/2find x


14
(x/15)(x/135) = 1

15
9/2/x = x/32 find x value

16
0.15  x2 =15

17
(3x)1/2 = 729 find the value of x

18
(x/169)1/2 = 54/39

19
  root of 14x18 x X=84

20
(0.0169 x X)1/2 =1.3

21
What is the smallest number by which 3600 be divided to make it a perfect cube?

22
By what least number 675 be multiplied to obtain a number which is a perfect cube?

23
The largest four-digit number which is a perfect cube is

24
The cube root of .000216 is

25
A = 51/2+1/51/2-1    B= 51/2-1/51/2+1 The value of a2 +ab+b2/ a2 -ab+b2

26
X= {7-4 (3)1/2} Then the value of (x + 1/x)

27
Root 2 = 1.414 the square root of root 2  -1/root 2 +1 is nearest to

28
Root 50 x root 98 is equal to?

29
The square root of (7 + 3 root 5) (7 - 3 root 5)

30
The value of root 0.16/0.4 =?


































































                                         
Answers of above problems
1.
Root of 6084   2)6084, 2)3042, 3)1521,
                           3)507, 13)169, 13
              6084= 22 x 32 x132 = 2 x 3 x 13= 78 
Find the square root of  1471369
1
1471369
1213

1

22
  47


  44

241
    313


    241

2423
      7269


      7269

Ans 1213.


3.
Evaluate :root 248 + root 51 +root 169
     248 + 51 + 13 =248 + root 64

4.
0.0009= 9/10000 = 32/1002 =(3/100)2=.03
5.
1 9/16 =   =(3/4)2

6.
  =1.732
1
3.000000
1.732

1

27
  200


  189

343
    1100


    1029

3462
      7100


      6924

7.
     root 176 +root 2401
(176)1/2 + (2401)1/2 = (176)1/2  +{(49)2}1/2= (225)1/2
           Ans. 15
8.
Square root of 225/729 – Square rout  of 25/144 + 
    square rout of 16/81 ?
     Ans. 152/272  - 52 /122 + 42+ /92 = 15/27 + 5/12 – 4/9 =
             LCM of 27,12,9= 3)9,4,3, 3)3,4,1 = 3x3x3x4=108
                 (60 + 45 -48 )/108 = 57/108

9
  (a+2)(b+3)/c + 1 if a=6 b=15, c= 3 find the value?
Ans. {6+2)(15+3)/(3+1)}1/2 = {8 x 18/4}1/2
             {144/4}1/2  = {{12/2}2}1/2  = Ans. 6
10
(86.49)1/2 + {(5+x)2}1/2 = 12.3  find x
Find the square root of  
9
86.49
9.3

81

183
  5.49


  5.49


    0










Ans 9.3
9.3+{(5+x)2}1/2=12.3
9.3+5+x=12.3
X=12.3-14.3=-2
11
x+y+root  xy If x = 6, y= 24 find ?
6+24 (6x24)1/2  = 30+ (144)1/2= 0+12=42
12
If y= 10 then what is the value of 10y root of         y3 – y2 = ?
Ans. 10x10 (103-102)1/2 = 100(1000-100) ½
              100 ( 900) ½  = 100 x (302) ½ = 3000
13
52/x =   root (169/289) find x
52/x= {132/172}1/2 = {(13/17)2}1/2
13x = 17 x 52  = x = (17 x 52)/13 =68
14
(x/15)(x/135) = 1
Ans. x2 =15 x 135 =2025  5x405,5x5x81,5x5x9x9
         x2  = 452 x= 45 
15
9/2/x = x/32 find x value
X2 = 9/2 x 32 =9x16 = 144= 122  x=12
16
0.15  x2 =15, 15/100 x 1/x2=15
X2 = 15 x 100/15 = 102 = x=10
17
(3x)1/2 = 729 find the value of x
Ans. (3x)1/2 = 35 , x/2 = 5, x=10
18
(x/169)1/2 = 54/39 Ans. x 1/2/13 =54/39
 X1/2 = (54 x 13)/39 = 18= x= 182
19
 Root of  14x18 x X=84, Squaring in both side
Ans. 14 x 18 x X = 84 x84
         X = (84x84)/14x18 = 6x84/18 = 2x84/6
         X = 28
20
(0.0169 x X)1/2 =1.3 squaring in both side
0.0169 x X = 1.3 x 1.3
   X = 1.69/0.0169 = 100
21
What is the smallest number by which 3600 be divided to make it a perfect cube?
3600= 23 x 52 x 32 x 2 = To make it perfect cube, it must be devidded by 52 x 32 x 2 = i.e450
22
By what least number 675 be multiplied to obtain a number which is a perfect cube?
675= 5x5x3x3x3 = 52 x33 = To make perfect cube multiply by 5
23
The largest four-digit number which is a perfect cube is
Ans. 9261 is a perfect cube satisfying the given property
24
The cube root of .000216 is
(.000216)1/3 = {216/106}1/3  = (63) 1/3/ {106}1/3
6/102 = 6/100 0.06
25
A = 51/2+1/51/2-1    B= 51/2-1/51/2+1 The value of a2 +ab+b2/ a2 -ab+b2+
Ans.  A = {51/2+1/51/2-1}  51/2+1/51/2+1 =(51/2+1)2/5-1
           = 5 +251/2 +1/4,  6 + 2(51/2)/4 =3+51/2/2
      B= {51/2-1/51/2+1}{51/2-1/51/2-1}={51/2-1}2/4
             3-51/2/2
A2 + B2 =  {3+51/2}2/4  - {3-51/2}2/4 = 2(9+5)/4 =7
26
X= {7-4 (3)1/2} Then the value of (x + 1/x)
  {7-4 (3)1/2} + 1/{7-4 (3)1/2} x {7+4 (3)1/2}               
                                                    /{7+4 (3)1/2}=
{7-4 (3)1/2} + {7+4 (3)1/2}/ 72 - 42 3=14/49-48 =14
27
Root 2 = 1.414 the square root of root 2  -1/root 2 +1 is nearest to
Ans. (21/2 -1) (21/2 -1)
         ---------------------    = (21/2 -1)2/2-1
            (21/2 +1) (21/2 -1)
          =1.414-1=.414
28
Root 50 x root 98 is equal to?
Ans. root 50 x 98 = (4900)1/2 = {(70)2}1/2 = 70
29
The square root of (7 + 3 root 5) (7 - 3 root 5)
Ans. 72 – {3 (5)1/2}2 = 49 – 9 x 5= 4 22 = Ans. 2
30
The value of root 0.16/0.4 =?

Ans. {.16/.40}1/2 = (16/40) ½ = (4/10) ½ = (0.4) ½= 
          0.63







No comments:

Post a Comment