A cube has a volume of 1,000 cubic feet. What is the length of an edge of the cube?

lina2011 [118]

Answer:

4. Functions: 1, 2, 4, 5, 7, 8, 11, 12

5. y = -1/2x+5/2, x ≤ -1; 2x +1, x > -1.

y = 2, x < 0; x, 0 ≤ x ≤ 3; 3 x > 3.

Step-by-step explanation:

4. A list of ordered pairs is a function of no x-values are re-used. In (3) and (6), the value x=2 is used more than once.

A graph represents a function if it passes the "vertical line test." A vertical line cannot intersect the graph in 2 or more points. (9) and (10) both fail that test.

If the relation is not listed here as being "not a function," then it is one of the answers to question 4.

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5. The first step in writing the equation of a piecewise function is to identify the pieces. These are generally bounded by points of discontinuity--jumps in the function value, or changes in the slope of lines.

The second step is to identify the section of the function that boundary points belong to. Solid dots are part of the function definition; open circles are not.

Left Graph

The left piece ends at x=-1. There is a solid dot attached to the left piece, so its definition will be for the domain x ≤ -1. That line has slope -1/2, since is drops 1 unit for each 2 to the right. If extended, it would intersect the y-axis at y = 2 1/2 = 5/2. So, the piece on the left is y = -1/2x + 5/2 for x ≤ -1.

The right piece starts at x=-1, but does not include that point. It has a rise of 2 for each 1 to the right, so its slope is 2. It crosses the y-axis at y=1, so the piece on the right is y = 2x + 1 for x > -1.

You can use the method of your textbook author to combine theses pieces into one equation. The method shown above is one way to do it.

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Right Graph

This graph has a discontinuity at x=0 and a change in slope at x=3. It can be described by 3 pieces. The point at x=0 does not belong to the left piece, but goes with the middle piece.

The left piece of the function is the constant 2, so has the equation y = 2 for x < 0.

The middle piece has a slope of 1 and a y-intercept of 0, so has the equation y = x for 0 ≤ x ≤ 3.

The point at x=3 belongs to both the middle piece and the right piece, so can be part of both function definitions, if you like. Generally, it is better form to include any given x-value in only one of the pieces of the function. So the equation for the right piece can be y = 3 for x > 3.

4 0

3 years ago

Pls help I’m failing math I’ll brainlest ASAP

skad [1K]

The equation 6 + 9a = 51 can help find out how many adults were in the group.

5 0

3 years ago

a certain triangle has a perimeter of 3067 mi. the shortest side measures 71 mi less than the middle side and the longest side m

UkoKoshka [18]

Answer:

The measure of the shortest side is 851 miles

Step-by-step explanation:

Let

x ----> the measure of the shortest side

y ---> the measure of the middle side

z ---> the measure of the longest side

we know that

The perimeter of triangle is equal to

$P=x+y+z$

$P=3,067\ mi$

so

$3,067=x+y+z$ ----> equation A

the shortest side measures 71 mi less than the middle side

so

$x=y-71$ ----> equation B

the longest side measures 372 mi more the the middle side

so

$z=y+372$ ----> equation C

substitute equation B and equation C in equation A

$3,067=(y-71)+y+(y+372)$

solve for y

$3,067=3y+301\\3y=2,766\\y=922$

Find the value of x

$x=y-71\\x=922-71\\x=851$

therefore

The measure of the shortest side is 851 miles

6 0

2 years ago

Suppose the average of 15 consectutive numbers is 15. What is the average of the first five numbers of the set?

Marina86 [1]

15x15= 225

15x + 105= 225

15x= 225-105

15x= 120

X=8

X+ (x+1) + (x+2) + (x+3)…etc all the way up too +(x+14)=225

The first five numbers of the set: 8, 9, 10, 11, 12

7 0

1 year ago

You row a canoe x miles per hour down a river for 20 minutes. On the return trip, you travel 1 mile per hour slower. The return

ozzi

Answer:

Total Distance = 2 miles

Step-by-step explanation:

We know D = RT where

D is distance

R is rate (speed)

T is time

First Leg:

Rate = x mph

Time = 20/60 = 1/3 hour

Hence, D = RT, Distance = x * 1/3 = x/3 miles

Second Leg:

Rate = x - 1

Time = 30/60 = 1/2 hour

Distance = (x - 1) * 1/2 = (x-1)/2

Total distance is the sum of both the legs, hence,

Total distance = $\frac{x}{3}+\frac{x-1}{2}=\frac{2x+3(x-1)}{6}=\frac{2x+3x-3}{6}=\frac{5x-3}{6}$ miles

Since both the distance are equal we can equate and solve:

$\frac{x}{3}=\frac{x-1}{2}\\2x=3x-3\\x=3$

Plugging this x = 3 into the total distance expression, we get:

$\frac{5x-3}{6}\\\frac{5(3)-3}{6}\\=2$

Total distance, 2 miles

5 0

3 years ago