C   =2pi*(d/2)         A = pi (d/2)^2

Part A

           A                                                    B

25.12  = 2pi *(8/2)                           9.42  = 2pi (3/2)

25.12  = 8pi                                     9.42  = 3pi

pi = 25.12 / 8                                   pi  = 9.42 / 3

pi ≈ 3.14                                          pi = 3.14

Part B

         A                                                     B

50.24  = pi (8/2)^2                          7.065  = pi (3/2)^2

50.24 = pi *4^2                               7.065 = pi (9/4)

50.24  = 16 pi                                 7.065 ( 4/9)   =  pi 

50.24/16  = pi                                   pi = 3.14

pi = 3.14

Part C

We see that pi is the  constant  ≈   3.14           (as we should expect  )

We  know  the adjacent side to D  =  11   and the  hypotenuse of this right triangle   = 15

The  trig function that relates  these   is the  cosine

So

cos D  = (11/15)       take  the arccos  (cosine inverse )  to find D

arccos (11/15)  = D  ≈  42.8° 

See my answer here  :

https://web2.0calc.com/questions/find-the-distance-between-the-graphs

This boils down to finding  the distance  from  the origin (0,0)  to the line

distance  =    l  2(0)  - 1(0)  + 4 l               4

                   ________________   =      ______   =     the radius of the  circle  

                    sqrt  [ 2^2 +1^2  ]               sqrt (5)

The area  of the  circle  =    pi (4/ sqrt (5) )^2   =  (16/5)pi units^2

Here's a graph  :    https://www.desmos.com/calculator/6d3n0brtjx

a + b = 4 + (√40)/2

a=1;b=45;phi=0;c=gcd(a, b);if(c==1, phi=phi+1, 0);a++;if(a<=b, goto3,0);print"Euler'sPhi =",phi

Euler's totient(Phi) = 24 such numbers.

The primes that factor 45  are  3  and 5....so....any integer not divisible  by either of these will be relatively prime to 45

[ 1 is not included....it  divides  every integer  ]

So we have     2,4,7,8,11,13,14,16,17,19,22,23,,26,28,29,31,32,34,37,38,41,43,44

23 integers

thanks you

answered at your other post, https://web2.0calc.com/questions/please-help-me_9416 

to the nearest degree what is the measure of 

tan X = 0.75     

Use a scientific calculator. 

You'll probably find a button labeled tan^–1 under 2nd function. 

Or, it might be labeled arctan instead.  They're the same thing. 

Type in .75 then tap the tan^–1 button. 

The display should then read 36.869897•••  

To the nearest degree, this rounds up to 37^o  

_.

At the end of the 6th day, there are 402 students with measles.

Please help now as soon as you can, I need this in the next 30 minutes.

(n+2)/n²  = .28

.28n² = n+2

.28n² -n-2=0

quadratic formula   n=   5       or   -1.42857<

Nevermind I got it

https://www.algebra.com/algebra/homework/Finance/Finance.faq.question.1054616.html

Thanks, CPhill!

f(x)=x+2

So

g(x)=1/(x+2)

f(-3)=-3+2=-1

So

g(-1)=1/(-1+2)

I will leave the rest to you

Yes I think you are!!!

See the following  :

Let  the circle with a radius of 8  be centered at the origin

Let the circle  with  the radius of 3  be centered at  P  = ( a , -5) 

The centers of the circles will be 11 units apart

And we  can   use a right triangle  with a hypotenuse of  11 = OP  and one leg of 5 = RP .....to find a  = OR we have

sqry [ 11^2  - 5^2] =  sqrt [96]  =  6sqrt (4)  =  OR  = a 

O = (0,0)     S = ( 4√6 , -8 )  = ( √ 96, -8)

So    OS   =sqrt   [ (√96)^2  + (-8)^2  ] =   sqrt  [ 96 + 64 ]  =  sqrt [ 160 ]  =  4 sqrt (10)  

Thanks, jugoslav.....here's another way without using trig.....

Let B  = (0,0)   A  = (5,0)   C  = (0,5)   and   D = (5,5)   P  = (2,0)

Slope  of  CP   =  -5/2

Equation of line through  CP .....  y = (-5/2)x + 5

Let S  be the intersection of  the line through segment  RQ  and the line through  CP

The x coordinate of this point   = 5....so we  have

y = -(5/2)(5)  + 5

y=  -25/2  +  5

y  = -15/2

So S = (5, -15/2)

So SQ  =  15/2

Using similar triangles

AQ / SA  =  DR/SD

AQ/ SA = DR  / (SA + AD)

1/ (15/2)  = DR  / ( 15/2  + 5)

(2/15)  = DR / (25/2)

DR = (25/2) (2/15)  = 50/30   = 5/3

If the person jogs  at a rate of 12 km  per hr  for 30 min......he/she  covers  12 km * 1/2  hr =  6 km

6 km =  6000m =  total distance jogged

Since this represents 10 laps.....then  1 lap =   6000 / 10   =    600m  = the perimeter of the  field

Perimeter =  2  [ L + W ]

And L  = 2W

So....substituting, we have that

600 = 2 [ 2W  + W]     divide both  sides  by 2

300 =   [2W  + W]

300   = 3W      divide  both sides by 3

100  = W        and  L = 2W = 2(100) =  200

Area =  L* W =     200 * 100  =    20000 m^2

How about the $longest$ post?

At the MP Donut Hole Factory, Niraek, Theo, and Akshaj are coating spherical donut holes in powdered sugar. Niraek's donut holes have radius 6 mm, Theo's donut holes have radius 10 mm, and Akshaj's donut holes have radius 18 mm. All three workers coat the surface of the donut holes at the same rate and start at the same time. Assuming that the powdered sugar coating has negligible thickness and is distributed equally on all donut holes, how many donut holes will Niraek have covered by the first time all three workers finish their current donut hole at the same time?

Hello Guest!

\(\frac{N\cdot Parts}{6^2mm^2}+\frac{T\cdot Parts}{10^2mm^2}+\frac{A\cdot Parts}{18^2mm^2}\\ =\frac{N}{36}+\frac{T}{100}+\frac{A}{324}\\ =\frac{N}{9}+\frac{T}{25}+\frac{A}{81}\\ = \frac{2025N+729T+225A}{18225}\cdot \frac{Parts}{mm^2}\)

In the period in which Akshaj 225 and Theo 729 coated donut holes,

Niraek coated 2025 donut holes.

  !

:))))))

8. Domain = All possible X values and Range = All possible y values (withouth duplicates. Can you calculate it now with the given points?

9. Same as #8

10. Remove duplicates, you'll be good to go with #8.

11. Also #8

12. Sometimes. All functions are relations, but not all relations are functions, by the vertical line test.

13. Graph the points. Next, determine if any two x coordinates are the same. If they are, it's a no for being a function. If they aren't then yes.

14. Follow #13

15. Follow #13, or just look at the x and y coordinates.

16. Are any x coordinates the same? (#13 again)

17.

a) We must not have the same x coordinate, by the vertical line test. So, because age is the x coordinate, age cannot go down, so it must be a function!

b) Probably not, unless the person is super healthy. The reasoning behind this is that as the age goes higher, the old person's might get shorter and thus the graph will have overlapping x coordinates, as you must have reached a certain point to regress back to it, as the word implies.

18. No, as there are two values for y when x = -1.

19. Yes, by the vertical line test.

20. No, as there are two values for y when x = 1 or 2.