English

Find the value of 5 correct to 2 decimal places; then use it to find the square root of 3-53+5 correct to 2 significant digits. - Mathematics

Advertisements
Advertisements

Question

Find the value of `sqrt5` correct to 2 decimal places; then use it to find the square root of `(3-sqrt(5))/(3+sqrt(5)` correct to 2 significant digits.

Sum

Solution

`sqrt(5)` = 2.236 = 2.24

  2.236
2 5.000000
4
42 100
84
443 1600
1329
4466 27100
26796
  304

 

 

 

 

 

 

 

 

 

 

`(3-sqrt(5))/(3+sqrt(5)`

= `sqrt(((3-sqrt(5))((3-sqrt(5))))/((3+sqrt(5))(3-sqrt(5))`

= `sqrt(((3-sqrt(5))^2)/((3)^2 - sqrt((5))^2)`

= `sqrt((3-sqrt5)^2)/(9-5)`

= `sqrt((3-sqrt(5)^2)/(4)`

= `((3-2.24))/(2)`

= `((0.76))/(2)`

= 0.38

shaalaa.com
  Is there an error in this question or solution?
Chapter 3: Squares and Square Root - Exercise 3 (B) [Page 42]

APPEARS IN

Selina Concise Mathematics [English] Class 8 ICSE
Chapter 3 Squares and Square Root
Exercise 3 (B) | Q 8 | Page 42
Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×