41.
The points, where the series solution of the Legendre differential equation \[\left( {1 - {x^2}} \right)\frac{{{d^2}y}}{{d{x^2}}} - 2x\frac{{dy}}{{dx}} + \frac{3}{2}\left( {\frac{3}{2} + 1} \right)y = 0\]        will diverge, are located at

42.
All solutions of the equation ez = -3 are

43.
The solution of the system of differential equations \[\frac{{dy}}{{dx}} = y - z\]   and \[\frac{{dz}}{{dx}} = - 4y + z\]   is given by (for A and B are arbitrary constants)

45.
Inverse Laplace transform of \[\frac{{s + 1}}{{{s^2} - 4}}\]  is .

46.
Consider the Bessel equation \[\left( {v = 0} \right),\,\frac{{{d^2}y}}{{d{z^2}}} + \frac{1}{z}\frac{{dy}}{{dz}} + y = 0.\]
Which one of the following statements is correct?

47.
If \[F\left[ {f\left( x \right)} \right] = \int_{ - \infty }^\infty {f\left( x \right){e^{ - ikx}}dx,} \]       then \[{{\hat F}^2}\left[ {f\left( x \right)} \right]\]   is equal to

48.
The value of the integral $$\int\limits_C {{z^{10}}dz,} $$  where C is the unit circle with the origin as the centre is

49.
If u (x, y, z, t) = f(x + iβy - vt) + g(x - iβy - vt), where f and g are arbitrary and twice differentiable functions, is a solution of the wave equation $$\frac{{\partial {u^2}}}{{\partial {x^2}}} = \frac{{{\partial ^2}u}}{{\partial {y^2}}} = \frac{1}{{{c^2}}}\frac{{{\partial ^2}u}}{{\partial {t^2}}}$$     then β is