A function f is onto if and only if, each element in the codomain of f is the image of at one element in the domain of f

A function f is onto if and only if, each element in the codomain of f is the image of at least one element in the domain of f.

Step-by-step explanation:

A function f is onto if and only if, each element in the codomain of f is the image of at least one element in the domain of f.

Let us consider a function f which maps the elements of X to each element in the domain of f, such that

f(1) = D

f(2) = B

f(3) = C

f(4) = C

From here, we can determine the domain and range, so

Domain  X of f = {1, 2, 3, 4}

Domain  Y of f =  {D, B, C}

Therefore, it is clear that every element in the codomain of f is the image of at least one element in the domain of f.

57 732

step-by-step explanation:

i dont really.know

(sin 42)/31. = sinx)/37

sinx = 37 (sin42)/31

= 37× 0.66/31 = 0.787

x= 51.9

other angle opposite to y = 180-51.9-42

= 180- 93.9 =86.1

so

sin42)/31 = sin 86.1)/y

0.021 = 0.997 /y

y= 0.997/0.021 =47.47