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
Karolina [17]
3 years ago
7

What is the value of cos θ given that (-2, 9) is a point on the terminal side of θ?

Mathematics
1 answer:
liq [111]3 years ago
3 0

Answer:

a)  cosθ  = \frac{-2\sqrt{85} }{85}

Step-by-step explanation:

<u><em> Step(i):</em></u>-

Given point ( x , y ) = ( - 2 , 3 )

We know that the polar co-ordinates

  x = r cos θ and y = r sinθ

where   r = \sqrt{x^{2} +y^{2} }  

            r = \sqrt{(-2)^{2} +(9)^{2} } = \sqrt{4+81} = \sqrt{85}

<u><em>Step(ii)</em></u>:-

           x = r cos θ

          cosθ   = \frac{x}{r}

      cosθ  = \frac{-2}{\sqrt{85} } = \frac{-2}{\sqrt{85} } X \frac{\sqrt{85} }{\sqrt{85} }

       cosθ  = \frac{-2\sqrt{85} }{85}

You might be interested in
the dimensions of kaly's new cell phone are 6 inches by 8 inches. her phone cost 30 per square inch how much did kayla pay for t
Ostrovityanka [42]

Answer:

1440

Step-by-step explanation:

6 x 8 = 48

48 x 30 = 1440

7 0
2 years ago
Help asappppp? i’m having trouble on wat the 1/4 point is
blagie [28]

Answer:

  (-14, 5.5)

Step-by-step explanation:

Perhaps the easiest way to find the 1/4 point is to find (x, y), then find the midpoint between that and M.

  (x, y) = 2M -(13, 25) = 2(-5, 12) -(13, 25) = (-23, -1)

Then the 1/4 point is ...

  ((-23, -1) +M)/2 = ((-23, -1) +(-5, 12))/2 = (-28, 11)/2 = (-14, 5.5)

_____

If we call the end points A(x, y) and B(13, 25), then we know ...

  M = (A+B)/2

  A = 2M -B . . . . we'll need this in a bit

and the 1/4 point Q is such that ...

  (Q -A)/(B -A) = 1/4

  4Q -4A = B -A . . . . cross multipliy

  Q = (B +3A)/4 = (B +3(2M -B))/4 = (6M -2B)/4 . . . . solve for Q

  Q = (3M -B)/2 . . . . reduce the fractions

  Q = (3(-5, 12) -(13, 25))/2 = (-28, 11)/2 = (-14, 5.5) . . . as above

6 0
2 years ago
Sarah wants to buy carpet for a square room with an area of 400sq ft.
zavuch27 [327]

Sarah wants to buy a carpet for a square room with an area of 400sq ft.

the length of the room is 20ft.

Area is a quantity that describes the extent of an area on a plane or curved surface. The area of ​​a planar region or planar region refers to the area of ​​a shape or planar layer, and surface area refers to the area of ​​an open surface or boundary of a three-dimensional object. Wikipedia

The area is the area occupied by a two-dimensional figure. That is, it is a quantity that measures the number of unit squares that cover the surface of a closed figure. The standard unit of area is the square unit, commonly expressed in square inches, square feet, and so on.

Learn more about area here

brainly.com/question/17713367

#SPJ1

6 0
1 year ago
(1/4)^3z-1=16^z+2x 64^z-2
SpyIntel [72]

Answer:

Step-by-step explanation:

3 0
2 years ago
SOMOEN DELETED ALL MY ASNWERS NOW I ONLY HAVE 13 POINTS WHY WHY WHYYYYYYYYY
Vedmedyk [2.9K]

Answer:

Maybe its because you give useless answers to get points.

Idiot.

7 0
2 years ago
Other questions:
  • You buy hammers for $30.00 a dozen and sell them for 3.50 each. What is the percent markup for the hammers?
    10·1 answer
  • I PROMISE I GIVE POINTS PLZ PLZ POINTS JUST ANSWER PLZ
    10·1 answer
  • 21. The total price of six cans of coke is $21.
    7·1 answer
  • If a=2 and b=3 then what does ab^2 equal
    8·2 answers
  • A student spends $48 on school supplies at a store where the sales tax is 7%. What's the total cost of the supplies
    8·2 answers
  • Whats 2+2 first person that pops of in my notification w be marked brainlietst good luck
    9·2 answers
  • Mr. Brown needs to price items that must be sold within 90​ days, and he has two options. In option​ A, Mr. Brown prices items a
    9·1 answer
  • The correct value of x is 3
    8·1 answer
  • What are the rules to remember while working with Proportional Relationships?
    12·1 answer
  • A 2 lb bag of sunflower seeds cost $1.29. Find the unit price. If needed
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!