At dawn and dusk, large amount of blue and violet light(shorter wavelength) has been scattered so, the light that is recieved by an observer is mostly of a longer wavelength and therefore appears to be red.

Here, f: A—>B

f(x)= (x-1)/(x+2)  ;  x   -2 

A= {-1,0,1,2,3,4}

B= {-2,1,-1/2,0,1/2,1/4,2/5}

Range = {-2,-1/2,0,1/4,1/2,2/5}

As range is not equal to codomain so the given function is not bijective. 

We can make it bijective by omitting {1} from set B 

Sunlight reaches Earth's atmosphere and is scattered in all directions by all the gases and particles in the air. Blue light is scattered more than the other colors because it travels as shorter, smaller waves. This is why we see a blue sky most of the time.

The stage of cell division in which paired homologous chromosomes get shortened and thickened is prophase I of meiosis. During this stage, the chromosomes condense and become visible as distinct structures, allowing for the homologous chromosomes to pair up and exchange genetic material through a process called crossing over. The shortening and thickening of the chromosomes during prophase I is important for proper alignment and separation of the homologous chromosomes during subsequent...