Step-by-step explanation:
The frequency and the wavelength of the wave have an inverse relationship.
The difference between a red shift and a blue shift is as follows;
Red shift: In the red shift, light changes as the object in space (such as star or galaxies) moves away from us then the light is shifted to red end.The light is shifted to a shorter frequency. In this case, the light is shifted to a longer wavelength.
Blue shift: In the blue shift, light changes as the object in space (such as star or galaxies) moves towards from us then the light is shifted to blue end. The light is shifted to a longer frequency. In this case, the light is shifted to a shorter wavelength.