Click to Chat
1800-1023-196
+91-120-4616500
CART 0
Use Coupon: CART20 and get 20% off on all online Study Material
Welcome User
OR
LOGIN
Complete Your Registration (Step 2 of 2 )
If a+b+c=3,a^2+b^2+c^2=13,a^3+b^3+c^3=27, then values of a b c which satisfy the three equations is
(a+b+c)2= a2+b2+c2+2 (ab+bc+ca)Or,9=13+2 (ab+bc+ca)Or,(ab+ba+ca)=-2Next,a3+b3+c3-3abc=(a2+b2+c2-ab-bc-ca)(a+b+c)or,27-3abc=(13+2)*9Or,27-3abc=135Or,3abc=27-135Or,abc=-36
I am sorry.I missed out that it asks for values of a,b,c not abc.Look at the 3rd equation.27 is cube of 3.So you know that one of the number is 3.You also kmow that a3+b3=0 in that case.It means that a=-b.Look at the 2nd equation given.If c=3(as obtained from 3rd eq) then 13-9=4.Also it means that a=-b=.Now look that these three values of a,b,c satisfies the first equation.So these are the answer.Please approve if helped.
Find solution of question on doubt solving app Instasolv
Post Question
Dear , Preparing for entrance exams? Register yourself for the free demo class from askiitians.
points won -