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Suppose that the functions u and w are defined as follows.

U(x) = x² +3
w (x) = sqrt of x+2
Find the following
(u • w)(2)=
(w • u) (2)=

1 Answer

3 votes

Answer(there are assumptions for this answer that you need to confirm and look at):

Assumptions:
u(x)=x^2+3 and
w(x)=√(x+2)

Answer if the operation is multiplication:

If you meant a closed dot which is the symbol for multiplication.


(u \cdot w)(2)=14


(w \cdot u)(2)=14

Answer if the operation is composition:

If you meant an open dot which is the symbol for composition.


(u \circ w)(2)=7


(w \circ u)(2)=3

Note: I don't know if you actually meant
w(x)=√(x+2) or if
w(x)=√(x)+2. Please let me know one way or the other.

Explanation:

If we assume the functions are:


u(x)=x^2+3


w(x)=√(x+2)


u \cdot w=w \cdot u since multiplication is commutative.


u(2)=2^2+3


u(2)=4+3


u(2)=7


w(2)=√(2+2)


w(2)=√(4)


w(2)=2

We are asked to find
(u \cdot w)(2) and
(w \cdot u)(2).

The order doesn't matter in multiplication.


(u \cdot w)(2)


u(2) \cdot w(2)


7 \cdot 2


14


(w \cdot u)(2)


w(2) \cdot u(2)


2 \cdot 7


14

Now you might have meant composition which symbolized with an open circle, not a closed one.


(u \circ w)(2)


u(w(2))


u(2) since
w(2)=2


2^2+3


4+3


7


(w \circ u)(2)


w(u(2))


w(7) since
u(2)=7


√(7+2)


√(9)


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