1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
ad-work [718]
3 years ago
15

(1 point) Find a⋅b if |a| = 2, |b| = 4, and the angle between a and b is −π7 radians.

Mathematics
1 answer:
AVprozaik [17]3 years ago
3 0

Answer:

a·b  = 7.2

Step-by-step explanation:

Given :

IaI = 2; IbI = 4 , \theta = -\pi/7

Using Dot product formula:

a·b = IaI IbI cos (\theta)

a·b  = (2) (4) (cos(-\pi/7[/tex])

a·b  = 7.2

Hence Dot product of vector a and b i s:

a·b  = 7.2

You might be interested in
Can some one help me on this plz
skad [1K]
Step 1
switch x and y
[x=-3y+27]

step 2
solve for y in steps
[x-27=-3y]

step 3 another solving
[(x-27)/-3=y]

step 4 simplify
[-1/3x+9=y]
(since -27/-3=+9)

attachment below

4 0
4 years ago
Sara wanted to cover her art project with shiny purple paper. Her project is in the shape of a cube and the area of a face is 9
Liula [17]
It will cost $4.50...
6 0
3 years ago
Read 2 more answers
Tommy and his family drove home from his grandparent's house in three and a half hours. If they drove at an average rate of 48 m
ivanzaharov [21]

Answer:

=168 miles

Step-by-step explanation:

5 0
3 years ago
In the card game Set, each card features a number of shapes, with four attributes:
LiRa [457]

A) The number of cards that are in a complete deck of Set is; 81

B) The number of unique sets are; 36

<h3>How to find the combination of a set of cards?</h3>

a) We are given;

Number of shapes = 1, 2 or 3

Colour = Red, Purple or Green

Shape = Oval, Diamond or Squiggle

Shading = Hollow, Shaded or Striped

Now, since a set is formed by all 3 cards, then we can say that;

Number of cards in a complete deck of set = 3⁴ = 81 cards

(b) Let us first find all sets = 3² * 4 * 3 = 108.

Thus;

Unique sets = 108/3

= 36 unique sets.

(c) There are 3 ways to choose the number of the cards from the given order.  

For the second one, there 2 choices, and then there is only 1 choice.  Thus; Number of ways to choose the numbers = 3 * 2 * 1 = 6.  

For the other attributes;

Number of ways = 6 * 6 * 24 *6 ways.

Now, since the order of cards doesn't matter in a set, then the number of sets where all three cards are the same for exactly 0 attributes is;

(6 * 6 * 24 *6)/3! = 864 sets

(d) If all the colors are the same, then;

Number of sets = 6 * 24 * 6/3! = 144 sets.  

If all the numbers are the same, then there are 144 sets which is also same for shapes and shading. Thus;

The number of sets where all three cards are the same for exactly 1 attribute is; 4 * 144 = 576

(e) There are C(4, 2) = 6 ways of choosing two attributes.  

For each of the two attributes, there are 3 options.  

For the other two attributes, there are 3 ways of assigning the choices. Thus, number of sets = 6*3*3*3*3 = 486 sets.

(f) There are C(4,3) = 4 ways of choosing which attributes are the same.  There are 3*3*4 = 36 ways to assign which is which for each of these three attributes, and there are 4 ways to assign the choices for the fourth attribute. Thus;

The number of sets where all three cards are the same for exactly 3 attributes = 4*36*4 = 576 sets.

Read more about Card combinations at; brainly.com/question/27447394

#SPJ1

6 0
2 years ago
WILL MARK BRAINLIEST. PLEASE HELP.<br> simplify:
Scilla [17]

Answer:

2+3\sqrt{5}

Step-by-step explanation:

Hi!

This is a lot of radicals, so it may seem tricky. Let's begin by simplifying all of the radicals that can be simplified.

We can see that \sqrt{75} can be simplified.

Taking prime factorization:

=\sqrt{5^2\cdot \:3}

which is:

=5\sqrt{3}

So an updated equation is \left(\sqrt{5}+\sqrt{3}-\sqrt{15}\right)\left(\sqrt{5}-\sqrt{3}\right)+5\sqrt{3}.

Now, we need to expand this:

First, let's expand the parenthesis:

\sqrt{5}\sqrt{5}+\sqrt{5}\left(-\sqrt{3}\right)+\sqrt{3}\sqrt{5}+\sqrt{3}\left(-\sqrt{3}\right)+\left(-\sqrt{15}\right)\sqrt{5}+\left(-\sqrt{15}\right)\left(-\sqrt{3}\right).

We can apply some of are rules:

\sqrt{5}\sqrt{5}-\sqrt{5}\sqrt{3}+\sqrt{3}\sqrt{5}-\sqrt{3}\sqrt{3}-\sqrt{15}\sqrt{5}+\sqrt{15}\sqrt{3}

And, now to simplifying!

Adding similar elements:

\sqrt{5}\sqrt{5}-\sqrt{3}\sqrt{3}-\sqrt{15}\sqrt{5}+\sqrt{15}\sqrt{3}

Simplifying and cleaning up each radical:

5-3-5\sqrt{3}+3\sqrt{5}.

Now all we have to do is add the similar elements (again.)

In doing so we reach an answer of \boxed{2+3\sqrt{5}}

Hope this helps!

- Sahkfam

3 0
3 years ago
Other questions:
  • Pls answer this one and I will mark it has brainlist
    15·1 answer
  • ABC =~~ CBD true or false
    14·1 answer
  • Evaluate 10x - 1 when x = 5
    14·2 answers
  • Solve equation for z
    8·2 answers
  • colton's gross pay id $1421.50 and his net pay is $973.48 what percent of his gross pay is take-home pay
    9·1 answer
  • Write 1/4 in decimals
    5·2 answers
  • "HOT PIZZA" is offering a 20% discount on all its pizzas.
    9·1 answer
  • Finding angle measures between intersecting lines .است Pa B 133 NOTE: Angles not necessarily drawn to scale.​
    11·1 answer
  • PLEASE HELP ME!!!!! NEED HELP ASAP!!!!!
    11·1 answer
  • In a school of 900 pupils, 30% are boys and 40% of the boys wear glasses.
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!