No products in the cart.

Use Euclid division leema to show …

CBSE, JEE, NEET, CUET

CBSE, JEE, NEET, CUET

Question Bank, Mock Tests, Exam Papers

NCERT Solutions, Sample Papers, Notes, Videos

Use Euclid division leema to show that cube of any positive integer is of the from 9m,9m+1or9m+8
  • 3 answers

Rashi Kashyap 6 years, 11 months ago

According to Euclid Division Lemma, a=bq+r,b<r<0 a1=3q+0 a2=3q+1 a3=3q+2 a1=3q. (Cubing both side) (a1)3= (3q)3 (a1)3=3q×3q×3q (a1)3=(9)3q3 Let 3q3=m (a1)3=9m (a2)3=3q+1. (Cubing both side) (a2)3=(3q+1)3 (a2)3=(3q)3+2×(3q)2×1+2×3q×(1)2+(1)3 (a2)3=9(3q3+2×(3q)2+6q)+1 let 3q3+2×(3q)2+6q=m (a2)3=9m+1 a3=3q+2. (Cubing both side) (a3)3=(3q+2)3 (a3)3=(3q)3+2×(3q)2×2+2×3q×(2)2+(2)3 (a3)3=9(3q3+2×(3q)2×2+2×3q×(2)2)+8 Let3q3+2×(3q)2×2+2×3q×4=m (a3)3=9m+8 Hence proved

Yogita Ingle 6 years, 11 months ago

<div> <div> <div>

Let x be any positive integer. Then, it is of the form 3q or, 3q + 1 or, 3q + 2.

So, we have the following cases :

Case I : When x = 3q.

then, x3 = (3q)3 = 27q3 = 9 (3q3) = 9m, where m = 3q3.

Case II : When x = 3q + 1

then, x3 = (3q + 1)3

= 27q3 + 27q2 + 9q + 1

= 9 q (3q2 + 3q + 1) + 1

= 9m + 1, where m = q (3q2 + 3q + 1)

Case III. When x = 3q + 2

then, x3 = (3q + 2)3

= 27 q3 + 54q2 + 36q + 8

= 9q (3q2 + 6q + 4) + 8

= 9 m + 8, where m = q (3q2 + 6q + 4)

Hence, x3 is either of the form 9 m or 9 m + 1 or, 9 m + 8.

</div> </div> </div>

Sujal Gupta 6 years, 11 months ago

Bshshshghdh
https://examin8.com Test

Related Questions

Find the nature of quadratic equation x^2 +x -5 =0
  • 0 answers
X-y=5
  • 1 answers
(A + B )²
  • 1 answers
Venu Gopal has twice
  • 0 answers
Prove that root 8 is an irration number
  • 2 answers
sin60° cos 30°+ cos60° sin 30°
  • 2 answers

myCBSEguide App

myCBSEguide

Trusted by 1 Crore+ Students

Test Generator

Test Generator

Create papers online. It's FREE.

CUET Mock Tests

CUET Mock Tests

75,000+ questions to practice only on myCBSEguide app

Download myCBSEguide App