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
Drupady [299]
3 years ago
15

Find ????⋅ ???? if |????|=3 , |????|=9 , and the angle between ???? and ???? is π2 radians.

Mathematics
1 answer:
mrs_skeptik [129]3 years ago
5 0

Answer:

a{\cdot}b=0

Step-by-step explanation:

It is given that,

Magnitude of a A, |A|=3

magnitude of B, |B|=9

The angle betwern a and b is \dfrac{\pi}{2}\ rad=90^{\circ}

Dot product,

a{\cdot} b=|a||b|\ \cos\theta\\\\a{\cdot} b=3\times 9\times \ \cos(90)\\\\a{\cdot} b=0

So, a.b is equal to 0.

You might be interested in
HELP PICTURE IS SHOWN
Salsk061 [2.6K]
The answer is the parallel line to one of a triangle.
6 0
3 years ago
So I am doing Zero and Negative Exponents in geometry and I am confused on whether (5.5)^0 is undefined or equal to 1. How do I
nevsk [136]

Anything to the power of zero should always equal 1.

There shouldn't be any reason why it will be undefined.

8 0
4 years ago
The sum of the digits of a two-digit number is 11. When the digits are reversed, the new number is 45 more than the original num
Crank

Answer:

Step-by-step explanation:

Let the 10s digit = x

Let the units digit = y

x +y = 11                                   Sum of the digits = 11

10x + y + 45 = 10y + x             Reversed number is 45 more  than original #

10x - x + y + 45 = 10y              We subtracted x from both sides.

9x + y + 45 = 10y                    Subtract y from both sides.

9x + 45 = 10y - y                     Combine the right

9x + 45 = 9y

Put x +  y = 11 into the equation just found.

9x + 45 = 9(11 - x)                     divide through by 9

x + 45/9 = 11 - x                        add x to both sides

2x + 5 =     11                            Subtract 5 from both sides

2x = 11 - 5

2x = 6                                       Divide by 2

x = 6/2

x = 3

x + y = 11

3 + y = 11        

y = 11 - 3

y = 8

Now check it out.

the original number is 38

the new number is 83 which the digits are reversed.

83 - 38 = 45 just as it should.  

6 0
3 years ago
NEED HELP ASAP PLEASE . End of quarter today
Ainat [17]

Answer:

I'm pretty sure it's A since B,C,and D wouldn't make sense.

7 0
3 years ago
What is the surface area of a sphere with a radius of 3m
Bas_tet [7]
The area is 113.1m If you want to double check go on google and look up surface area of a sphere. A calculator will come up. Hope this helped.
4 0
3 years ago
Other questions:
  • Please help!! due very soon
    7·1 answer
  • Given that m<a = 16°, m<c = (8x+20)°, and m<d =128°, what is m<d​
    6·1 answer
  • What is the total price of a $45 pair of jeans after a 6.5% sales tax is added?
    13·1 answer
  • Find the value of c that makes the trinomial a perfect square.<br> x2+8x+c
    13·1 answer
  • Use the cubic model y = 10x3 − 12x to estimate the value of y when x = 3.
    6·1 answer
  • Which expression can be used to find the surface area of the following rectangular prism?
    8·2 answers
  • Use the rule to find the output when the input is –6.
    15·1 answer
  • Find the median: In a particular year, approximately 1.7 million people took the mathematics section of a college achievement te
    12·1 answer
  • For A brainlist ** explain
    5·1 answer
  • a a Members of a softball team raised $1579.50 to go to a tournament. They rented a bus for $1175.50 and budgeted $25.25 per pla
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!