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
n200080 [17]
3 years ago
15

What is the sum of the first 9 terms of 7+21+63+...

Mathematics
1 answer:
attashe74 [19]3 years ago
7 0

Answer:

Step-by-step explanation:

7

21

+63 =91

You might be interested in
PLZ HELP I REALLY NEED IT
Ber [7]

Answer:

18 Inches

Step-by-step explanation:

1 foot + 12 in + 6 in = 18 in

6 0
3 years ago
Find the area lying outside r=6cos(theta) and inside r=3+3cos(theta)
Sloan [31]
The area bounded by the 2 parabolas is A(θ) = 1/2∫(r₂²- r₁²).dθ between limits θ = a,b... 

<span>the limits are solution to 3cosθ = 1+cosθ the points of intersection of curves. </span>
<span>2cosθ = 1 => θ = ±π/3 </span>

<span>A(θ) = 1/2∫(r₂²- r₁²).dθ = 1/2∫(3cosθ)² - (1+cosθ)².dθ </span>
<span>= 1/2∫(3cosθ)².dθ - 1/2∫(1+cosθ)².dθ </span>
<span>= 9/8[2θ + sin(2θ)] - 1/8[6θ + 8sinθ +sin(2θ)] .. </span>
<span>.............where I have used ∫(cosθ)².dθ=1/4[2θ + sin(2θ)] </span>
<span>= 3θ/2 +sin(2θ) - sin(θ) </span>

<span>Area = A(π/3) - A(-π/3) </span>
<span>= 3π/6 + sin(2π/3) -sin(π/3) - (-3π/6) - sin(-2π/3) + sin(-π/3) </span>
<span>= π.</span>
7 0
3 years ago
There are two cell phone plans available from Cells Phones R Us company. Plan A charges $35 a month plus $0.05 for every text me
Yuri [45]

if PLAN A is cheaper than PLAN B then,

P (A) < P (B)

30+0.01t < 20+0.05t      (subtract 0.05t from both sides)

29.95-0.04t < 19.95        (subtract 29.95 from both sides)

-0.04t < -10                      (divide both sides by -0.04)

t > 250

So plan A is cheaper than plan B when you send more than 250 texts.

Hope it helps.

5 0
3 years ago
Ethan was busying marshmallows for a family bonfire. Each bag of marshmallows was 250 g. If Ethan wanted to buy 3 kg of marshmal
sp2606 [1]
It's 12 bags (3000/250)
6 0
3 years ago
Read 2 more answers
Sin x = cos<br><br>I do not understand trig ​
frez [133]

Answer:

tanx = 1

Step-by-step explanation:

I assume you mean sinx = cosx

In this case we have to recognize that tanx = sinx / cosx

So if we divide cosx over we can get tanx

So:

Cosx divided by itself gives us 1

sinx / cosx = 1

tanx = 1

3 0
3 years ago
Other questions:
  • Determine whether the triangles must be congruent. If so, name the postulate or theorem that justifies your answer. If not, expl
    11·1 answer
  • josh wanted to buy a bicycle but didn't have enough money. After josh told his troubles to sam slick, sam said,"I can fix that.
    11·2 answers
  • An $42 item was marked down by 50%<br><br> what is the new cost of the item?
    15·1 answer
  • PLEASE HELP ME!! IM STUCK!!
    14·2 answers
  • What number is the product of two different prime numbers greater than 7
    5·1 answer
  • Will mark brainliest for whoever answers
    10·1 answer
  • Find the value of x in the triangle shown below.
    7·2 answers
  • Pls help I can't even under stand it
    6·1 answer
  • Please help im literally crying i cant fail this please ​
    7·1 answer
  • What value is missing from the table ?
    6·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!