Answer:
Consider f: N → N defined by f(0)=0 and f(n)=n-1 for all n>0.
Step-by-step explanation:
First we will prove that f is surjective. Let y∈N be any natural number. Define x as the number x=y+1. Then x∈N, and f(x)=x-1=(y+1)-1=y. We conclude that f is surjective.
However, f is not injective. Take x1=0 and x2=1. Then x1≠x2 but f(x1)=0 and f(x2)=x2-1=1-1=0. We have shown that there are two natural numbers x1,x2 such that x1≠x2 but f(x1)=f(x2), that is, f is not injective.
Note:
If 0∉N in your definition of natural numbers, the same reasoning works with the function f: N → N defined by f(1)=1 and f(n)=n-1 for all n>1. The only difference is that you consider x1=1, x2=2 for the injectivity.
The 3rd one. (where the round part of the graph is at 0, 0) because that is where the y axis meets
Answer:
hope that it helps you any
Step-by-step explanation:
first hour she drove 60mi
second hour she drove 50mi
third hour she drove 70mi
fourth hour she drove 20mi
fifth hour she drove 75mi
all together she drove 275miles
take 275 divide it by 5 you get an average of 55mph
Answer:
20 flapjacks is the answer.
The answer is 244 because you add 35 to 287 then subtract 78 and it equals 244
