Young's interference experiment problem

[downwithsocks]

Homework Statement

Figure 35-25 shows two sources S1 and S2 that emit radio waves of wavelength λ in all directions. The sources are exactly in phase and are separated by a distance equal to 1.5λ. The vertical broken line is the perpendicular bisector of the distance between the sources. (a) If we start at the indicated start point and travel along path 1, does the interference produce a maximum all along the path, a minimum all along the path, or alternating maxima and minima? Repeat for (b) path 2 and (c) path 3.

Homework Equations

$$\Delta$$L = dsin$$\theta$$ m$$\lambda$$ - bright fringes
$$\Delta$$L = dsin$$\theta$$ (m+.5)$$\lambda$$ - dark fringes

The Attempt at a Solution

I'm really not quite sure how to apply the concepts from Young's experiment to this problem. I know how interference produces minima and maxima on a stationary surface a set distance away, but I'm not sure how to relate that to a moving path perpendicular to where that stationary surface would be.

 

[1994Bhaskar]

Hey where's the diagram?

 

[downwithsocks]

Sorry it showed up for me. Should work now.