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Unformatted text preview: 19. Since x = r cos and y = r sin , we have = cos + sin r x y = -r sin + r cos . x y Also, xi + yj = (cos )i + (sin )j r ^ = -yi + xj = -(sin )i + (cos )j. r ^ r= Therefore, 1 ^ ^ r+ r r = cos2 + sin cos i x y + cos sin + sin2 j x y + sin2 - sin cos i x y + - cos sin + cos2 j x y = i+ j = . x y ...
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This note was uploaded on 03/08/2012 for the course MATH 120 taught by Professor Onurfen during the Spring '12 term at Middle East Technical University.
- Spring '12