Page 267 - DMTH201_Basic Mathematics-1
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Basic Mathematics – I




                    Notes
                                                      dy
                                          Example: Find   , if,  x 2  y 2  a 2
                                                      dx
                                   Solution: Differentiate w.r.t. x
                                                dy
                                           2x  2y   0
                                                dx
                                               dy
                                             2y      2x
                                               dx
                                            dy   2x
                                            dx  2y

                                            dy   x
                                            dx   y

                                                      dy
                                          Example: Find   , if,  x 2  y 2  2x  4y  6  0
                                                      dx
                                   Solution: Differentiate w.r.t. x
                                                dy      dy
                                            2x  2y  2 4      0
                                                dx      dx
                                       Cancelling 2, we get

                                              dy      dy
                                          x y     1 2     0
                                              dx      dx
                                             dy
                                                 y  2   x  1
                                             dx
                                             dy     x  1
                                             dx    y  2

                                                      dy
                                          Example: Find   , if,  e x y  e x
                                                      dx

                                   Solution: Differentiate w.r.t. x
                                          x y d
                                         e       x y   e x
                                             dx
                                                    dy
                                         i.e.,e x y  1   e  x
                                                    dx

                                                dy   e x  1
                                             1       x y  y
                                                dx  e     e
                                             dy  1 e  y
                                         i.e.,
                                             dx   e  y








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