Page 216 - Engineering Mathematics Workbook_Final
P. 216

Numerical Methods

                                                                                                             nd
                   the solution at the end of the first                  is  x = 1, then the value of x after 2
                                                                             0
                   time step is __________                               iteration is ____________.
                          [GATE-2017-CE SESSION-I]                                  [GATE-2015-ME-SET-3]


            31.    There is no value of x that can                35.    In Newton Raphson iterative method,
                   simultaneously satisfy both the given                 the initial guess value ( X  )  is
                                                                                                   ini
                   equation. Therefore, find the ‘least                  considered as zero, while finding the
                   squares error’ solution to the two                    roots of the equation
                   equations, i.e., find the value of x that               ( ) x = − +    4x +      3
                                                                                  2 6x −
                                                                                            2
                   minimizes the sum of squares of the                    f                    0.5x . The
                                                                                    
                   errors in the two equations 2x = 3, 4x                correction  x , to be added to  X  in
                                                                                                          ini
                   = 1.                                                  the first iteration is ______________.

            32.    Using given data points tabulated                                 [GATE-2015-CE-SET-2]
                   below, a straight line passing through
                   the origin is fitted using least squares       36.    The quadratic equation
                                                                           2
                                                                                    4 0 is the solved
                   method. The slope of the line is                      x −  4x + =
                                                                         numerically, starting with the initial
                                                     2
                    x      y          xy            x                    guess  x =  3. The Newton-Raphson
                                                                                 0
                    1     1.5        1.5            1                    method is applied once to get a new
                    2     2.2        4.4            4                    estimate and then the Secant method
                    3     2.7        8.1            9                    is applied once using the initial guess
                                    xy =  14     x =  2  14            and this new estimate. The estimated

                                                                         value of the root after the application
                   (a) 0.9               (b) 1                           of the Secant method is __________.
                   (c) 1.1               (d) 1.5
                                                                                     [GATE-2015-CE-SET-1]

            33.    The Newton-Rapshon method is used              37.    The Newton-Raphson method is used
                   to solve the equation                                 to solve the equation
                            3
                                  2
                    f  ( ) x =  x − 5x + 6x − = . Taking
                                         8 0
                                                                                   3
                                                                                          2
                                                                          f  ( ) x =  x − 5x +  6x − = .
                                                                                                   8 0
                   the initial guess as  x = 5, the solution
                                                                                                         5
                   obtained at the end of the first                      Taking the initial guess as  x = , the
                   iteration is ___________.                             solution obtained at the end of the
                                                                         first iterations is _______.
                               [GATE-2015-ME-SET-2]
                                                                                     [GATE-2015-EC-SET-3]
            34.    Newton-Rapshon method is used to
                   find the roots of the equation,                38.    How many distinct values of x satisfy
                                                                                          ( )
                   x +  2x + 3x − 1 0. If the initial guess              the equation sin x =    x  / 2, where x
                                   =
                          2
                     3
                                                                         is in radians?



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