This problem refers to questions 8 and 9

The diagram below shows all the antinodal lines (solid) and nodal lines (dashed) due to two point sources tapping a water surface (the two dots in the middle of the circle are the two point sources). The sources are separated by an unknown distance d. The sources lie along a horizontal line.

NOTE: Please type the answers on a computer not handwriting, If for some questions you can't draw with your computer, just explain in words what your drawing would look like.