Answer:
A relational database stores data in a series of tables so that the data models a mathematical theory of relations. The model allows for queries based on projection, selection, and join, among other operations, and connects the data in the tables by way of keys.
Answer:
Well, I guess in a formal sense you could call relational algebra a type of logic, which puts it into the realm of ‘math’, though I don’t think most mathematicians would look at it as being a very significant area, more ‘applied logic’ than anything else.
That being said, relational algebra DOES present some formalisms in the shape of relations, tuples, normalizations, and denormalization, etc. There is also a model of sequential operations and thus the underpinnings of the ACID database concept.
Since the overwhelming primary use of RA has been as a way to structure our ideas about SQL RDBMSes there isn’t really a lot of deep theory there. I don’t think anyone has really built any other models of RA beyond an RDBMS. There have been limited non-SQL RDBMS implementations, but AFAIK none of them are really actively maintained today.
A basketball-player scores a free-throw with probability 0.9. What is the probability that her first miss occurs on the 6th shot
Answer:
[tex]Pr = 0.059049[/tex]
Step-by-step explanation:
Given
[tex]p = 0.9[/tex] --- probability of scoring
Required
Probability that his first miss is his 6th shot
Let q represent the event that he did not score.
Using complement rule:
[tex]q = 1 - p = 1 - 0.9 = 0.1[/tex]
The event that his first miss is his 6th is represented as:
p p p p p q ---- That he scoress the first 5 attempts
So, the probability is:
[tex]Pr = p^5 * q[/tex]
[tex]Pr = 0.9^5 * 0.1[/tex]
[tex]Pr = 0.059049[/tex]
7. The revenue for the school play is given by: R= -50t^2 + 300t , where “t” is the ticket price in dollars. The cost to produce the play is given by: C = 600-50t. Determine the ticket price that will allow the school play to break even. (Note: breaking even means that revenue = cost.) Sketch the graphs of both equations as seen on your calculator (indicate the window you used
in the space provided).
Answer:
R= -50t^2 + 300t
-50tt(t-6)
-50(t-12)
so lets say that they sold 10 dollar tickets
-5000(4)
so they would lose -20000 dollars
-50(-2)
and the play would cost 100 dollars
Hope This Helps!!!
solve for x. Round to the nearest tenth, if necessary.
Answer:
50.8°
Step-by-step explanation:
In ∆ IJK :-
sin x = 6.2/8 x = sin -¹ ( 62/80) x = sin -¹ ( 31/40 ) x = 50.8°Please help me with this
Answer:
52 in^2
Hope this helps!
Uma empresa do ramo de confecções produz e comercializa calças jeans. Se x representa a quantidade produzida e comercializada (em milhares de reais) e L(x) = -x² + 8x – 16 representa o lucro (em milhares de reais) da empresa para x unidades, então quando L(x) = 0 a empresa terá produzido e comercializadas quantas unidades dessas calças jeans? *
Answer:
I am in 5 classso i did not known answer
A bag contains 13 blue marbles, 12 red marbles, 6 yellow marbles, and 8 green marbles. What is the probability of picking a red marble, putting that one back and then picking another red marble?
Answer:
(12/39) * (12/39) or 16/169
Step-by-step explanation:
Which inequality describes the graph?
Answer:
1 describe the inequality graph
Find the length of the line AB if A is (-2,3) and B is (5,7)
Answer:
[tex]{ \tt{length = \sqrt{ {( - 2 - 5)}^{2} + {(3 - 7)}^{2} } }} \\ = \sqrt{65} \\ = 8.06 \: units[/tex]
HELP. Drag the tiles to the correct boxes to complete the pairs.
Match each product of complex numbers with its value.
Answer:
[tex]i^{2} (2i^{2} -5)[/tex]
[tex]2i^{2} \times i^{2} -5i^{2}[/tex]
[tex]2(-1)(-1)-5(-1)[/tex]
[tex]2+5[/tex]
[tex]=7[/tex] [tex]i^{2}(2i-5)[/tex]
------------------
[tex]i^{2} (3+i^{2} )[/tex]
[tex]i^{2} \times 3+i^{2} \times i^{2}[/tex]
[tex](-1)3+(-1)(-1)[/tex]
[tex]-3+1[/tex]
[tex]-2[/tex] [tex]=i^{2} (3+i^{2} )[/tex]
---------------------
[tex]2i(2i-i^{3} )[/tex]
[tex]2i\times 2i-i^{3} \times2i[/tex]
[tex]4i^{2} -2i^{4}[/tex]
[tex]4(-1)-2(1)[/tex]
[tex]-4-2=[/tex]
[tex]-6=2i(2i-i^{3} )[/tex]
-------------------
[tex]i(4i^{3} -i)[/tex]
[tex]4i^{3} \times i-i\times i[/tex]
[tex]4i^{4} -i^{2}[/tex]
[tex]4(1)-(1)[/tex]
[tex]4+1=5[/tex]
--------------------
ANSWER:
[tex]-6\Longrightarrow 2i(2i-i^{3} )[/tex]
[tex]5\Longrightarrow i(4i^{3} -i)[/tex]
[tex]7\Longrightarrow i^{2} (2i-5)[/tex]
[tex]-2\Longrightarrow i^{2} (3+i^{2} )[/tex]
----------------------------
Hope it helps...
Have a great day!!
Maths problem
Mass
Solve the problems below.
1. A box has 3 books. Each book has a mass of 250g.
(a) What is their total mass?
Answer:
250 x 3 = 750g
750g is your final answer
Can someone help me with this math homework please!
Answer:
The first answer
Step-by-step explanation:
Domain refers to the set of x values and range refers to the set of y values. Since x goes from 0 to 3, and does not exclude any values within those numbers, the first answer applies to that set.
Answer:
option 1
that is
{t| 0 <= t <= 3}
Step-by-step explanation:
as the graph plots height ove time
time will be the domain, taken on the x axis, with values ranging from 0 to 3.
so the domain is
{t| 0 <= t <= 3}
A rectangle has a perimeter of 80 cm and its length is 1 cm more than twice its width. Find the dimensions of a rectangle given that its perimeter is 80 cm and its length is 1 cm more than twice its width. Set up your solution using the variables L for the length, W for the width, and P for the perimeter. Part a: Using the definition of the perimeter, write an equation for P in terms of L and W. Part b: Using the relationship given in the problem statement, write an equation for L in terms of W. Solve the equations from parts a and b. Part c: The length is ? Cm. Part d: The width is? Cm.
Answer: (a) P = 6W + 2
(b) L = 2W + 1
(c) Width = 13cm
Length = 27cm
Step-by-step explanation:
The formula for perimeter of a rectangle is 2(length + width). Since the length is 1 cm more than twice its width, then the length will be:
L = (2 × W) + 1
(b) L = 2W + 1
Therefore, P = 2(L + W)
P = 2( 2W + 1) + 2W
P = 4W + 2 + 2W
(a) P = 6W + 2
Since perimeter is given as 80cm. Therefore,
P = 6W + 2
6W + 2 = 80
6W = 80 - 2
6W = 78
W = 78/6
W = 13
Width is 13cm
Length = 2W + 1
Length = 2(13) + 1
Length = 27cm
The width of the rectangle is 13cm and the length is 27cm.
Description of a rectangleA rectangle is a quadrilateral. Opposite sides are equal. The four angles in a rectangle is equal to 90 degrees.
The formula for determining the perimeter of a rectangle = 2x (length + width)
P = 2(L + W)
Perimeter = 80 length = 1 + 2w Width = w Determining the values of width and length80 = 2(1 + 2w + w)
80 = 2(1 + 3w)
40 = 1 + 3w
40 - 1 = 3w
39 = 3w
w = 13cm
Length = 1 + 2(13) = 27cm
To learn more about rectangles, please check: https://brainly.com/question/16595449
Find the height h of the triangle.
Answer:
A, 12 times the square root of 3
Step-by-step explanation:
24 sqaured plus 12 squared=432
square root of 432=20.9
12 times the sqaure root of 3=20.9
Type your response in the box. Imagine that this graph represents the distance Brianna travels to get to her babysitting job with respect to time. Describe a relation that the graph may represent.
Answer:
Brianna left home and drove 3 miles in 6 minutes. She then stopped for 4 minutes to pick up coffee. Finally, she traveled the last 4 miles in 6 minutes to arrive at her babysitting job.
Step-by-step explanation:
This answer is from Plato.
What are the steps in order of operations
Which of the Following best describes a cylinder?
Answer:
D
Step-by-step explanation:
all the options seems similar..but i can find the D more suitable
if f(x)= 3^x+10x and g(x)= 2(x) = 2x - 4 find (f+g)(x)
Answer:
(f + g)(x) = 3^x + 12x -4
Step-by-step explanation:
Here, we want to get the value of (f + g)(x)
Mathematically, we have this as;
(f + g)(x) = f(x) + g(x)
= 3^x + 10x + 2x-4
= 3^x + 12x -4
Hey guys please try this is kinda urgent. what is the value of x in the geometric progression. 16/9 , x, 1, y.
============================================================
Explanation:
Let r be the common ratio. Also, we'll make r nonzero, i.e. [tex]r \ne 0[/tex]
Multiplying this common ratio by any term gets us the next term of the geometric sequence.
16/9 is the first term, so that makes (16/9)*r the second term
Since (16/9)r is the second term, the third term is (16/9)r*r = (16/9)r^2
Set this equal to 1 and solve for r.
(16/9)r^2 = 1
r^2 = 1*(9/16)
r^2 = 9/16
r = sqrt(9/16) or r = -sqrt(9/16)
r = 3/4 or r = -3/4
Now that we know what r is, we can determine the second term
If r = 3/4, then,
(16/9)*r = (16/9)*(3/4) = 4/3
Or if r = -3/4, then,
(16/9)*r = (16/9)*(-3/4) = -4/3
So the second term is either 4/3 or -4/3 depending on which r value you go for.
Ethan buys 4 pack of muffins. he uses a coupon an saves 2$ off total.
Which expression represents his total cost?
Answer:
4x-2
Step-by-step explanation:
X=muffins
the ratio of boys to girls is 4:3 .if there are 24boys ,how many are there?
Answer:
[tex]{ \bf{total \: ratio = 4 + 3 = 7}} \\ { \tt{let \: population \: be \: p}} \\ \frac{4}{7} \times p = 24 \\ 4p = 168 \\ p = 42 \\ { \bf{there \: are \: 42 \: people}}[/tex]
Boys to girls- 4:3
Boys and girls- 24 and x (let the girls be x)
4/3=24/x
=4x= 72
= x= 72/4
= x= 18 girls
Ans: There are 42 children (24+18)
the value of x-y+xy if x=1 y=1 is
Answer:
1
Step-by-step explanation:
x-y+xy=1-1+1*1=0+1=1
Answer:
1
Step-by-step explanation:
X=1
Y=1
here,
x-y+xy=1-1+1×1
or,x-y+xy=0+1=1
Staysafe❤
D=rt What does T equal? Lol how is this possible
Answer:
t = D/r
Step-by-step explanation:
you rearrange the equation so that is the subject. when you bring something over the equal sign, it reverses the function so D = r×t becomes t = D/r
The gradient of the line passing through A (2,3), B (k,7) is
23
23
. Find the value of k. help pls
Given:
The gradient of the line passing through A(2,3), B(k,7) is [tex]\dfrac{2}{3}[/tex].
To find:
The value of k.
Solution:
The gradient or slope of a line is:
[tex]m=\dfrac{y_2-y_1}{x_2-x_1}[/tex]
The gradient of the line passing through A(2,3), B(k,7) is [tex]\dfrac{2}{3}[/tex]. So,
[tex]\dfrac{2}{3}=\dfrac{7-3}{k-2}[/tex]
[tex]\dfrac{2}{3}=\dfrac{4}{k-2}[/tex]
On cross multiplication, we get
[tex]2(k-2)=4(3)[/tex]
[tex]2k-4=12[/tex]
[tex]2k=12+4[/tex]
[tex]2k=16[/tex]
Divide both sides by 2.
[tex]k=\dfrac{16}{2}[/tex]
[tex]k=8[/tex]
Therefore, the value of k is 8.
subtract the following rational expressions
[tex] \frac{8k}{9k - 4} - \frac{3k^3}{2k + 7} [/tex]
please show all work
Answer:
-27k^4 +12k^3+16k^2+56k
---------------------
(9k-4)(2k+7)
Step-by-step explanation:
8k 3k^3
--------- - -----------
9k-4 2k+7
Get a common denominator
8k *(2k+7) 3k^3 *(9k-4)
--------- - -----------
(9k-4)(2k+7) (9k-4)(2k+7)
Combine
8k *(2k+7) -3k^3 *(9k-4)
---------------------
(9k-4)(2k+7)
Distribute
16k^2+56k -27k^4 +12k^3
---------------------
(9k-4)(2k+7)
-27k^4 +12k^3+16k^2+56k
---------------------
(9k-4)(2k+7)
if u help me i will give you brainliest <3
Answer:
a) 6
b) 12:35 ( not so sure about this one)
Step-by-step explanation:
a)
distance = speed * time
ruths distance = 4* 1.5 (because it takes her 1h 30 mins)
distance = 6miles
b) 1/4 here is quarter so, 15mins
10:30 and then add 50 mins to that.
she leaves at 11:20 and takes 1h and 15 mins ( 75mins) to walk home
so 11:20 + 1h 15min
= 12:35
hope this helps :)
Answer:
a) 6 miles
b) 12:35 pm
Step-by-step explanation:
a) 9 am to 10:30 am = 1 hour and 30 mins = 1.5 hours
4mph x 1.5 = 6miles
b) 10:30 am + 50 mins = 11:20 am
1 hour = 60 mins
60/4 = 15 mins
1 1/4 = 1 hour 15 mins
11:20 am + 1 hour 15 mins = 12:35 pm
Choose the smallest number 3 1/8 or 10/3
Answer:
10/3
Step-by-step explanation:
31/8= 3.8
10/3= 3.3
At Billy's school, 80 students come to school by bicycle or by car. Together, the vehicles they arrive to school in have 270 wheels. How many of each are used
Answer:
x = number of bicycles = 35
y = number of cars = 55
Step-by-step explanation:
Let
x = number of bicycles
y = number of cars
x + y = 80 (1)
2x + 4y = 270 (2)
From (1)
x = 80 - y
Substitute x = 80 - y into (2)
2x + 4y = 270 (2)
2(80 - y) + 4y = 270
160 - 2y + 4y = 270
- 2y + 4y = 270 - 160
2y = 110
y = 110/2
y = 55
Substitute y = 55 into (1)
x + y = 80 (1)
x + 55 = 80
x = 80 - 55
x = 35
x = number of bicycles = 35
y = number of cars = 55
The velocity of a car over five hours is given by v(t) = 60 ln(t + 1), 0 < t < 5
in kilometers per hour. What is the total distance traveled from t = 0 to t = 5?
Round your answer to the nearest whole number and do not include units.
Answer:
345
Step-by-step explanation:
The velocity of a car over five hours is given by:
[tex]\displaystyle v(t)=60\ln(t+1),\, 0 \leq t \leq 5[/tex]
And we want to find the total distance traveled from t = 0 to t = 5.
Recall that distance is the integral of the absolute value of the velocity function. Since we want to find the total distance traveled from t = 0 to t = 5, our limits of integration are t = 0 and t = 5. Hence:
[tex]\displaystyle D=\int_0^5 |\underbrace{60\ln(t+1)}_{v(t)}|\, dt[/tex]
Since v(t) ≥ 0 for all t in the interval [1, 5], we can remove the absolute value. Use a calculator:
[tex]\displaystyle D=60\left(6\ln(6)-5)=345.0334...\approx 345[/tex]
CH 2. PPLYNOMIALS 1. The number 0 is called a
Step-by-step explanation:
The number 0 is called a. zero polynomial. binomial.
zigya
How many terms are in the algebraic expression
Also, What do they mean by "Terms"
Answer:
There are 4 terms
Step-by-step explanation:
A term is a single mathematical expression. Terms can be identified with a plus or minus sign in front of them. Terms can also be multiplied and divided.
So, in this case, the terms are:
-7
12x^4
-5y^8
x
