Macaulay's Method

Q. For determining the deflection 'y' of a loaded beam at a distance 'x' by Macaulay's method, which one or more of the following is/are used?
1. The basic differential equation for deflection $El\frac{d^{2}y}{d{x}^2}=-M;$ where El is the flexural rigidity of the beam, M is the bending moment.
2. Successive integration of the differential equation given in 1.
3. Known positions of zero deflection in the beam.
Select the correct answer using the codes given below:

1. 1 only
2. 1 and 2
3. 3 only
4. 1, 2 and 3

Q. Assertion (A): Macaulay's method to determine the slope and deflection at a point in a beam is suitable for beams subjected to concentrated loads and can be extended to uniformly distributed loads.
Reason (R): Macaulay's method is based upon the modification of moment area method. This is applicable to a simple beam carrying a single concentrated load but by superposition, this -method can be extended to cover any kind of loading.

1. both A and R are true and R is the correct explanation of A
2. both A and R are true but R is not a correct explanation of A
3. A is true but R is false
4. A is false but R is true