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
inysia [295]
3 years ago
6

Find the angle between u=(8, -2) and v=(9,3) Round to the nearest tenth of a degree.

Mathematics
2 answers:
Kryger [21]3 years ago
5 0

Answer:

the angle between u=(8, -2) and v=(9,3) is 32.5°

Step-by-step explanation:

u=(8,-2)=(u1,u2)→u1=8, u2=-2

v=(9,3)=(v1,v2)→v1=9, v2=3

We can find the angle between two vectors using the formula of dot product:

u . v =║u║║v║cos α   (1)

And the dot product is:

u . v = u1 v1 + u2 v2

u . v = (8)(9)+(-2)(3)

u . v = 72-6

u . v = 66


║u║=√(u1²+u2²)

║u║=√((8)²+(-2)²)

║u║=√(64+4)

║u║=√(68)

║u║=√((4)(17))

║u║=√(4)√(17)

║u║=2√(17)


║v║=√(v1²+v2²)

║v║=√((9)²+(3)²)

║v║=√(81+9)

║v║=√(90)

║v║=√((9)(10))

║v║=√(9)√(10)

║v║=3√(10)


Replacing the known values in the formula of dot product (1):

u . v =║u║║v║cos α

66 = 2√(17) 3√(10) cos α

Multiplying:

66 = 6√((17)(10)) cos α

66 = 6√(170) cos α

Solving first for cos α: Dividing both sides of the equation by 6√(170):

\frac{66}{6\sqrt{170} }=\frac{6\sqrt{170}cos \alpha}{6\sqrt{170} }

\frac{66}{6\sqrt{170}}=cos\alpha

Simplifying: Dividing the numerator and denominator on the left side of the equation by 6:

(66/6)/(6√170/6)=cosα→11/√170=cosα→cosα=11/√170

cosα=11/13.03840481→cosα=0.84366149

\alpha=cos^{-1}0.84366149\\\alpha=32.47119205^{\°}\\ \alpha=32.5^{\°}

Hatshy [7]3 years ago
3 0

Answer:

The answer is 32.5 degrees.

You might be interested in
By what percent will a fraction change if its numerator is decreased by 20% and its denominator is decreased by 60%?
Vedmedyk [2.9K]

Answer:

The fraction will increase by 100%

Step-by-step explanation:

Say the fraction is x/y. The question is telling us to decrease x by 20% (i.e. 0.8x) and to decrease y by 60% (i.e. 0.4y):

= \frac{0.8x}{0.4y}\\= 2 (\frac {x}{y})

You can see that by applying these changes, the new fraction is actually double the old fraction (i.e. will increase by 100%).

6 0
3 years ago
Read 2 more answers
A taxi company charges $1.00 for the first mile (or part of a mile) and 20 cents for each succeeding tenth of a mile (or part).
meriva

Step-by-step explanation:

solving functions separately.

1st:  from given data taxi charges $1.00 for the first mile.so it is first rule of function.

y_{1} =1 , 0

2nd: the company charge $0.20 per tenth of a mile.so 2nd rule of the function will  be

y_{2} =1+0.2.10(x-1)

simplifying

y_{2} =1+2(x-1)

y_{2} =x+2x-2

y_{2} =x ,  1

piece wise function is f(x)={2 ,  0<x<1

                                              {x ,  1<x<2

the graph of the function is given below

7 0
3 years ago
Explain how to identify the terms 3y-4-5y
anastassius [24]
You would add the y's together and then you have your answer and then answer is -2y-4 
7 0
3 years ago
The show 14 / 6 on a number line
Serhud [2]
I drew this by hand. sorry I it does not help.

3 0
3 years ago
Don't stick with your computer, do smth that make you happy IRL<br> btw, don't report this please
Mrac [35]
What makes me happy irl is nothing really, I only exist to make others happy
5 0
3 years ago
Read 2 more answers
Other questions:
  • PLEASE PLEASE HURRY!!!!!!!
    9·1 answer
  • Convert 3.5 in to a fraction with 5 repeating
    9·2 answers
  • Which of the following expressions is equivalent to y^-3?
    11·1 answer
  • What is the equation of the line shown in this graph?
    15·1 answer
  • Find the distance between the two points.
    11·1 answer
  • 1.What is the slope of this graph?
    9·1 answer
  • Of all the calls in the first quarter of year 5, how many were abandoned
    11·1 answer
  • Does anyone know the answer???
    10·2 answers
  • Sam buys a game console and a cartridge for 546 . The cartridge costs 1/5 as much as the game console . Find the cost of the gam
    5·2 answers
  • F r e e g i v e a w a y
    14·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!