prove that

Asked by  | 7th Oct, 2008, 09:55: AM

Expert Answer:

we know that (a+b)3 = a3 +b3 + 3a2b + 3ab2

(a-b)3 = a3 - b3 + 3a2b - 3ab2

so (m+n)2/3 = a2/3 (cosA+sinA)2

(m-n)2/3 = a2/3 (cosA-sinA)2

so(m+n)2/3 + (m-n)2/3 = a2/3 ( (cosA+sinA)2 + (cosA-sinA)2 )

=2 a2/3

 

 

 

 

Answered by  | 29th Nov, 2008, 04:18: AM

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