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3 years ago

Does the following equation determine y to be a function of x? y square=x+3

Mathematics

1 answer:

Phantasy [73]3 years ago

5 0

Answer:

∴ y² = x + 3 is not a function

Step-by-step explanation:

* Lets explain how to solve the problem

- The definition of the function is every input (x) has only one

output (y)

- Ex:

# y = x + 1 where x ∈ R , is a function because every x has only

one value of y

# y² = x where x ∈ R , is not a function because y = ±√x, then one

x has two values of y

* Lets solve the problem

∵ y² = x + 3

- Find y by taking √ for both sides

∴ y = ± √(x + 3)

- That means y = √(x + 3) and y = - √(x + 3)

∵ (x + 3) must be greater than or equal zero because there is no

square root for negative number

∴ x + 3 ≥ 0 ⇒ subtract 3 from both sides

∴ x ≥ -3

∴ x must be any number greater than or equal -3

- Let x = 0

∴ y = √(0 + 3) = √3 and y = - √(0 + 3) = -√3

∴ x = 0 has two values of y ⇒ y = √3 and y = -√3

- Any value of x greater than or equal 3 will have two values of y

∴ y² = x + 3 is not a function

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Express the system as AX = B; then solve using matrix inverses

Wittaler [7]

Answer with explanation:

1. The given equations are

3x -5 y=2

-x+2 y= 0

⇒The matrix in the form of , AX=B, is

$A=\left[\begin{array}{cc}3&-5\\-1&2\end{array}\right] ,\\\\ X=\left[\begin{array}{c}x&y\end{array}\right],\\\\B=\left[\begin{array}{c}2&0\end{array}\right]$

$\rightarrow X=A^{-1}B\\\\\rightarrow X=\frac{Adj.A}{|A|}\times B$

Adj.A=Transpose of cofactor of Matrix A

$Adj.A=\left[\begin{array}{cc}2&1\\5&3\end{array}\right] ,\\\\ |A|=6-5\\\\|A|=1\\\\\left[\begin{array}{c}x&y\end{array}\right]=\left[\begin{array}{cc}2&5\\1&3\end{array}\right] \times \left[\begin{array}{c}2&0\end{array}\right]\\\\x=4, y=2$

The given equations are

x+y-z=2

x+z=7

2 x +y+z=13

⇒The matrix in the form of , AX=B, is

$A=\left[\begin{array}{ccc}1&1&-1\\1&0&1\\2&1&1\end{array}\right]\\\\ X=\left[\begin{array}{ccc}x\\y\\z\end{array}\right]\\\\B= \left[\begin{array}{ccc}2\\7\\13\end{array}\right]\\\\\rightarrow X=A^{-1}B\\\\\rightarrow X=\frac{Adj.A}{|A|}\times B\\\\a_{11}=-1,a_{12}=1,a_{13}=1,a_{21}=-2,a_{22}=3,a_{23}=1,a_{31}=1,a_{32}=-2,a_{33}=-1\\\\|A|=1\times(0-1)-1\times(1-2)-1\times(1-0)\\\\=-1+1-1\\\\|A|=-1\\\\Adj.A=\left[\begin{array}{ccc}-1&-2&1\\1&3&-2\\1&1&-1\end{array}\right]$

$\frac{Adj.A}{|A|}=\left[\begin{array}{ccc}1&2&-1\\-1&-3&2\\-1&-1&1\end{array}\right]\\\\X=A^{-1}B\\\\\left[\begin{array}{ccc}x\\y\\z\end{array}\right]=\left[\begin{array}{ccc}1&2&-1\\-1&-3&2\\-1&-1&1\end{array}\right]\times\left[\begin{array}{ccc}2\\7\\13\end{array}\right]\\\\x=3,y=3,z=4$

7 0

3 years ago

Data were collected on the number of days per week that members visit a certain fitness center. The values varied from 0 to 7, a

pshichka [43]

Answer:

Step-by-step explanation:

choice A is not guaranteed since the values varied from 0 to 7.

choice B seems alright, but doesn't include about or anything about the long run.

choice C is incorrect because 50% are less than 3.12 and 50% are greater than 3.12.

choice D seems pretty good, since it says average, long run, approach, etc.

choice E is incorrect because it says "will be". It is not definite.

8 0

3 years ago

A scalene triangle has sides measuring 200 feet, 107 feet, and 221 feet. What is the

jenyasd209 [6]

Answer:

P = 528

Step-by-step explanation:

P = a + b + c = 200 + 107 + 221 = 528

8 0

3 years ago

150% as a simplified fraction

Ipatiy [6.2K]

Answer:

It would be 3/2 as 1/2 is 50%, 2/2 or 1 is 100% and 3/2 is 150%

Step-by-step explanation:

7 0

3 years ago

You brought 1.5 dozen bagels to school. A dozen bagels cost $5.98. You used a coupon that took $1.00 off of the total. How much

shusha [124]

Answer: (7.97)

Step-by-step explanation:

1 dozen = 5.98

.5 dozen = 2.99

5.98+2.99=8.79 8.79- the 1.00 is (7.97)

hope this helps!

3 0

3 years ago