The diagram shows a sketch of a wave pattern, over a short period of time. Which description of this wave is correct?

8.1.1 explain and use the principle of superposition in simple applications

8.1.2 show an understanding of experiments that demonstrate stationary waves using microwaves, stretched strings and air columns

8.1.3 explain the formation of a stationary wave using a graphical method, and identify nodes and antinodes

8.2.1 explain the meaning of the term diffraction

8.2.2 show an understanding of experiments that demonstrate diffraction including the diffraction of water waves in a ripple tank with both a wide gap and a narrow gap

8.3.1 understand the terms interference and coherence

8.3.2 show an understanding of experiments that demonstrate two-source interference using water ripples, light and microwaves

8.3.3 understand the conditions required if two-source interference fringes are to be observed

8.3.4 recall and solve problems using the equation m = $\frac{ax}{n}$ for double-slit interference using light

8.4.1 recall and solve problems using the formula d sin i = nm

8.4.2 describe the use of a diffraction grating to determine the wavelength of light (the structure and use of the spectrometer are not included)

8.5 pending