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
malfutka [58]
3 years ago
7

Find a ⋅ b. a = 4i - 4j, b = 4i + 5j

Mathematics
2 answers:
Alchen [17]3 years ago
8 0

ANSWER

a \cdot \: b =  - 4

EXPLANATION

The dot product of two vectors

a = xi + yj

and

b = mi + nj

is given by

a \cdot \: b = mx + ny

The given vectors are:

a = 4i - 4j

b = 4i + 5j

Applying the above definition of dot products, we obtain:

a \cdot \: b = 4 \times 4 +  - 4 \times 5

a \cdot \: b = 16   - 20

a \cdot \: b =  - 4

svetoff [14.1K]3 years ago
7 0

Answer:

value of a.b = -4

Step-by-step explanation:

We need to find a.b

a= 4i-4j

b = 4i+5j

We know that i.i =1, j.j=1, i.j =0 and j.i=0

a.b = (4i-4j).(4i+5j)

a.b = 4i(4i+5j)-4j(4i+5j)

a.b = 16i.i +20i.j-16j.i-20j.j

a.b = 16(1) +20(0)-16(0)-20(1)

a.b = 16 +0-0-20

a.b = 16-20

a.b =-4

So, value of a.b = -4

You might be interested in
Billy stacked six pieces of wood on top of one another. If each piece
Sliva [168]
The answer would be 175 feet tall

6 0
3 years ago
Read 2 more answers
HELP ASAP (40 POINTS)
frez [133]

Answer:

c i think because the problem =-

-  \frac{1}{4}

4 0
2 years ago
Describe how the range of a data set can help describe its variability.
katovenus [111]

Answer:

The range is defined as the difference between the term with the highest value and the term with the lowest value. This statistic is used to measure the variability of a series of data because it provides information on how far apart the values of a tail of the distribution are from the values at the other end of the tail.

Imagine that you manufacture a type of spare part for cars that must have a measurement of 10 cm with a margin of error of 1 cm.

This is:

10 ± 1 cm

Then you expect your manufacturing process to produce pieces with identical dimensions, that is, with little variability.

If you randomly select a sample of n pieces and measure them, the variability is expected to be low, so that your process is of quality, then expect a low range preferably less than 1 cm.

{10, 10.1, 10.5, 9.8, 9,6, 10.2} Range= 10.5 - 9.6 = 0.9 cm <em> low variability</em>

But if you find that the range is up to 8 cm, this would mean that not all pieces measure around 10 cm, it means that the variability of the measurements is high.

{14, 12, 11, 8, 7, 11, 12, 15} Range = 15 - 7 = 8 cm   <em>high variability </em>

6 0
3 years ago
Read 2 more answers
the price per share of a stock decreased from $90 per share to $36 per share. by what percent did the price of the stock decreas
givi [52]

Answer:

60%

Step-by-step explanation:

we know that

the price per share of a stock decreased from $90 per share to $36 per share

In this problem

$90 represent the 100%

so

using proportion

Find out what percentage represent the difference of ($90-$36)

($90-$36)=$54

Let

x ----> the percentage of the difference

\frac{100\%}{\$90}=\frac{x}{\$54}\\\\x=54(100)/90\\\\x=60\%

8 0
3 years ago
Factors of 9.52? Please help. Google won’t tell
Elina [12.6K]

Answer:

9.52 x 1

4.26 x 2

4 x 2.38

Hope that helps

4 0
3 years ago
Other questions:
  • WILL GIVE BRAINLIEST!
    10·1 answer
  • Kelly was baking bread but could only find her 1/8 cup measuring cup. She needs 1/4 cup sugar,3/4 cup whole wheat flour, and 1/2
    12·1 answer
  • PLEASE I NEEED THIS FAST!!
    8·2 answers
  • What is the solution to this equation?
    7·1 answer
  • PLEASE HELP ME ON 6-11 AND SHOW WORK PLEASE!!
    9·2 answers
  • I need help preferably fast but take your time
    6·1 answer
  • I need help with this math problem
    9·1 answer
  • Please give me the correct answer.Only answer if you're very good at math.Please don't put a link to a website.​
    6·1 answer
  • 2. Use the conversion table to convert the following metric units into the given English units.
    15·1 answer
  • If the slope is 6 and the point is (4,-7), point-slope form is
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!