consider f:R to R defined by f(x)=5x+3 show that f is a bijective function
Answers
Answer:
First you need to show that the function is one-to-one: put into precise mathematical terms, this means
f(x)=f(y)⇒x=y
Or in English: if f(x)=f(y) , then x=y
Suppose f(x)=f(y) which means
3x−5=3y−5 so 3x=3y which means x=y .
Therefore, f(x) is one-to-one.
Now we need to show f(x) is onto R
This means that R=Rng(f) . Now the
range of f is the set of values that f maps to from the
domain. Now, we need to show that
R⊆Rng(f) (we know that
Rng(f)⊆R since f is a function)
So, suppose y∈R and let
x=y+53 . Since y∈R
that means x∈R . Now consider
f(x) .
f(x)=3(y+53)−5
f(x)=y+5−5=y . This means y∈Rng(f) ;
thus, R⊆Rng(f) and
Rng(f)⊆R which together
mean R=Rng(f) ; thus, f is onto.
Since f is one-to-one and onto, it is by definition a
bijection. Q.E.D
Step-by-step explanation:
Answer:
So this is your perfecct answer