MY CART (5)

Use Coupon: CART20 and get 20% off on all online Study Material

ITEM
DETAILS
MRP
DISCOUNT
FINAL PRICE
Total Price: Rs.

There are no items in this cart.
Continue Shopping
Menu
Grade: 10
        If a+b+ c= 1,( a *a)+ (b*b) + (c*c) = 9 and find (a*a*a) + (b*b* b) + (c* c*c) =1 Find (1/a)+(1/b) + (1/c)
9 months ago

Answers : (1)

Adarsh Bajpai
36 Points
							
Given:a+b+c=1
            a^2+b^2+c^2=9
            a^3+b^3+c^3=1
Now as we all know
(a+b+c)^2=a^2+b^2+c^2+2 (ab+bc+ca)
now putting the values 
(1)^2=(9)+2 (ab+bc+ca)
1-9=2 (ab+bc+ca)
-8=2 (ab+bc+ca)
therefore,  -4=(ab+bc+ac)       …......... [1]
now, a^3+b^3+c^3-3abc=(a+b+c)(a^2+b^2+c^2-ab-bc-ac)
 Again putting values
 1-3abc=(1){9-(ab+bc+ac)}
1-3abc=9-(-4)
1-3abc=9+4
1-3abc=13
1-13=3abc
-12=3abc 
therefore,  abc=-4
Now,1/a+1/b+1/c=bc+ac+ab/abc
                               = -4/ -4
                               =1
9 months ago
Think You Can Provide A Better Answer ?
Answer & Earn Cool Goodies

Get Extra Rs. 1,590 off

COUPON CODE: SELF10


Course Features

  • 731 Video Lectures
  • Revision Notes
  • Previous Year Papers
  • Mind Map
  • Study Planner
  • NCERT Solutions
  • Discussion Forum
  • Test paper with Video Solution


Course Features

  • 101 Video Lectures
  • Revision Notes
  • Test paper with Video Solution
  • Mind Map
  • Study Planner
  • NCERT Solutions
  • Discussion Forum
  • Previous Year Exam Questions


Get Extra Rs. 233 off

COUPON CODE: SELF10

Ask Experts

Have any Question? Ask Experts

Post Question

 
 
Answer ‘n’ Earn
Attractive Gift
Vouchers
To Win!!! Click Here for details