65. Using differentials, find the approximate value of each of the following up to 3 places of decimal.

0 6 Views | Posted 4 months ago
Asked by Shiksha User

  • 1 Answer

  • V

    Answered by

    Vishal Baghel | Contributor-Level 10

    4 months ago

    (i) Let y= ?x : Let x = 25 and x = 0. 3.

    Then, ?y = ?x+?x?x

    =?25.3?25

    =?25.3?5

    ?25.3=5+?y?????????????????y~dy.

    = 5 + dy

    5+(dydx)Ax.

    =5+12?x?x.

    =5+12?25?0.3

    =5+0.32*5

    = 5 + 0.03

    ?25.3=5.030

    (ii) ?49.5

    A.(ii)

    Let y = ?x. Let x = 49 and x = 0.5.

    Then, ?y=?x+?x?x.

    =?49.5?49

    ?49.5=7+?y=7+(dydx)?x

    =7+12?x?x

    =7+12?49*(0.5)

    =7+0.514

    = 7 + 0.0357.

    ?49.5=7?035

    (iii) ?0.6

    A.(iii)

    Let y = ?x. Let x = 0.64 and ?x = 0.04.

    Then, ?y=?x+Ax?x

    =?0.64-0.04?0.64.

    =?0.6?0.8

    ?0.6=0.8+?y=0.8+(dydx)?x

    =0.8+12?x?x

    =0.8+12?0.64*(??0.04)

    =0.8?0.042*0.8

    = 0.8 - 0.025.

    = 0.775.

    (iv) (0.009)13

    A.(iv)

    Let y=x13 Let x = 0.008 and ?x = 0.00 1.

    Then, ?y = [x+?x]13?[x]13

    =(0.009)13?(0.008)13

    (0.009)13=0.2+?y=0.2+dydx??x

    =0.2+13(x13)2?x

    =0.2+13[(0.008)13]2*(0.001)

    =0.2+0.0013*(0.0)2=0.2+0.0010.12

    = 0.2 + 0.0083.

    = 0.208.

    (v) (0.999)110

    A.(v)

    Let y=x110. Let x = 1 and ?x = -0.001

    Then, ?y=(x+?x)110?x110

    =(0.999)110?(1)110

    ?1(0.999)110=1+Ay

    =1+dydx?x.

    =1+110x910*?x

    =1?0.00110(.1910)=1?0.00110=1?0.0001

    = 0.999.

    (vi) (15)14

    A.(vi)

    Let y=x14. Then, x = 16 and ?x = 1.

    Then, ?y=(x+Ax)14?x14.

    =(15)14?(16)14

    ?(15)14=2+Ay=2+dydxAx

    =2+14x34?(?1)

    =4?14(16)34

    =2?14*8

    =4?132

    =64?132=6332=1.968

    (vii) (26)13

    A.(vii)

    Let y=x13. Let x = 27 and ?x = 1.

    Then, ?y=(x+?x)13?x13

    =(26)13?(27)13

    ?(26)13=3+4y=3+dydxAx=3+13x23Ax,

    =3?13(2F)23

    =3?127

    =81?127=8027=2.962.

    (viii) (255)14

    A.(viii)

    Let y=x14. Let x = 256 and ?x = 1.

    Then, ?y=(x+?x)14?x14.

    =(255)14?(256)14

    ?(255)14=(256)14+4y=4+dydxAx.

    =4+14x34?4x

    =4?14(256)34

    =4?1256

    =1024?1256

    =1023256=3.996

    (ix) (82)14

    A.(ix)

    ...more