Answers

2015-09-24T17:50:16+05:30

This Is a Certified Answer

×
Certified answers contain reliable, trustworthy information vouched for by a hand-picked team of experts. Brainly has millions of high quality answers, all of them carefully moderated by our most trusted community members, but certified answers are the finest of the finest.
I will us e the symbol  A in place of Ф.

x = r cos A  and y = r sin A

dx = - r sin A  dA + Cos A  dr

dx / x² = [- r Sin A  dA + Cos A  dr ] / (r² cos²A)
dy / y² = [ r cos A dA  + sin A dr  ] / (r² Sin² A)

dx / x²  + dy /y²
   =  [ - r Sin³ A dA + Cos A Sin² A dr + r Cos³A dA + Sin A Cos²A dr]
            / (r² Sin²A Cos²A)
  = [ r (CosA - SinA) (Cos²A+CosA SinA + Sin²A) dA + (CosA Sin²A + SinA Cos²A) dr ]  / [r² Sin²A Cos²A ]

  = [ r (cosA - Sin A)(1+cosA SinA) dA + CosA SinA (sinA + CosA) dr ]
               / [r² Sin²A Cos²A]
 
  = [ (x - y) (1 + xy/r²) dA +  xy/r³ (x + y) dr ] / x²y²


1 5 1
click on thank s button above please
select best answer pls