if f(r)= 3.14 r^2 what is f(3)

Answer:

Step-by-step explanation:

To make this easier we are going to make a table and fill it in with the pertinent information. That's the first step; the second one is figuring out how to use the information in the table to come to some sort of a viable and reasonable (and hopefully correct) answer. The table will look like this:

                     d        =        r        *        t

Car 1

Car 2

What we know first off is that the time in question, the IMPORTANT time is 9 hours. That they left at the same time doesn't give us any numbers to put into our table or any useful information. We are looking at what happens at 9 hours. So that's what goes into the t column:

                    d        =        r        *        t

Car 1                                                   9

Car 2                                                  9

What we are then told is that after this 9 hours they are a certain distance apart. We'll come back to that. One car is traveling 10 km/h slower than the other, but since we don't know what the rate of the other car is either, they are both unknown. And it just so happens that this the information we are asked to solve for.

                  d        =         r        *       t

Car 1                                r        *       9

Car 2                           r - 10     *       9

Now, since d = rt, we multiply the rate times the time and fill in the distance each has gone in 9 hours:

               d        =        r        *        t

Car 1       9r       =        r        *       9

Car 2   9r - 90  =     r - 10     *       9

The distance between these 2 cars after that 9 hours is 910 km, therefore:

distance that car 1 traveled + distance that car 2 traveled = 910 km:

9r + 9r - 90 = 910 and

18r - 90 = 910 and

18r = 1000 so

r = 55.56 km/hr

and the other car is going 10 km/hr slower at 45.56 km/hr

Answer:  [tex]\sqrt{2}[/tex]

======================================================

Explanation:

Rewrite each trig function terms of sine and/or cosine. Then use the unit circle to find that,

[tex]\cot(90^{\circ})\cos(45^{\circ}) + \sec(45^{\circ})\\\\\frac{\cos(90^{\circ})}{\sin(90^{\circ})}\cos(45^{\circ}) + \frac{1}{\cos(45^{\circ})}\\\\\frac{0}{1}*\frac{\sqrt{2}}{2} + \frac{1}{(\sqrt{2})/2}\\\\\frac{2}{\sqrt{2}}\\\\[/tex]

Now rationalize the denominator

[tex]\frac{2}{\sqrt{2}}\\\\\frac{2\sqrt{2}}{\sqrt{2}*\sqrt{2}}\\\\\frac{2\sqrt{2}}{\sqrt{2*2}}\\\\\frac{2\sqrt{2}}{\sqrt{4}}\\\\\frac{2\sqrt{2}}{2}\\\\\sqrt{2}[/tex]

Which is the exact value of [tex]\sec(45^{\circ})[/tex]

The portion [tex]\cot(90^{\circ})*\cot(45^{\circ})[/tex] evaluates to 0 and goes away.

Answer:

b) 78.5

Step-by-step explanation:

distance you will move = circumference of wheel = πd = π(25) = 78.53981

This is because the two chords are the same length, so they are the same distance away from the center.

We can prove this by drawing the following red segments as shown below. These segments are radii of the circle. After forming the two right triangles, note how we can use the hypotenuse leg (HL) theorem to prove the triangles congruent. So this leads to x = 9 because the corresponding pieces of the triangles must be the same.

Answer:

60cm

Step-by-step explanation:

3×4×5

you multiply each side together

Answer:

10cm² (check explanation)

Step-by-step explanation:

using the formular;

A = ½ x Base x Height

(You did not specify which one is base etc)

I'll use any parameter;

If height = 5cm, base = 4cm

The area = (5 x 4)/2

= 20/2

= 10cm²

Answer:

a) 3.5 cm / month

b y = 3.5(x-1) + 4, x >= 1

Step-by-step explanation:

the plant grew 32-4 = 28 cm in 9-1 = 8 months.

so, the growth rate is 28 cm / 8 months = 7 cm / 2 months, or (to norm it to a typical 1 unit denominator) 3.5 cm per month.

x = months of growth

y = height of plant

so, considering the "start" of 4 cm after one month, the equation is

y = 3.5(x-1) + 4, x >= 1

since we don't know anything about anything that happened before the first month was over, we cannot validate this equation for anything x<1.

Answer:

8.6023

Step-by-step explanation:

length = √[(x2-x1)^2+(y2-y1)^2]

=√[(1-6)^2+(-1--8)^2] =√74 =8.6023

Answer:

Step-by-step explanation:

Answer:

i don't know

Step-by-step explanation:

i don't know

Answer:

14, 21

Step-by-step explanation:

LCM : least common multiplier.

x + y = 35

LCM = 42

means that there is a combination of 2 of the following divisors of 42 :

2, 3, 6, 7, 14, 21

so, which two of these numbers can create the sum of 35 ?

only 14 and 21

the answer of this question is (-2,2)

Answer:

The answer is 36°.

Hope it helps.

Step-by-step explanation:

• • •

Answer:

Please find attached the drawing of quadrilateral KLMN created with MS Whiteboard using the Ink to Shape command

(a) Two pairs of opposite sides are [tex]\overline {KN}[/tex], [tex]\overline {LM}[/tex] and [tex]\overline {KL}[/tex], [tex]\overline {NM}[/tex]

(b) Two pairs of opposite angles are ∠LKN, ∠LMN, and ∠KLM and ∠KNM

(c) Two pairs of adjacent sides are [tex]\overline {KN}[/tex], [tex]\overline {NM}[/tex] and [tex]\overline {KL}[/tex], [tex]\overline {LM}[/tex]

(d) Two pairs of adjacent angles are ∠LKN, ∠KLM and ∠LMN, ∠KNM

Step-by-step explanation:

Answer: x = 36

Step-by-step explanation:

[tex]\frac{2}{3} x-4=20\\\\\frac{2}{3} x=20+4\\\\\frac{2x}{3} =24\\\\2x=24*3\\\\x=\frac{72}{2} =36[/tex]

Answer:

The answer is D

Step-by-step explanation:

use the quadratic formula, plug and chug, and voila!

Based on the relationship between Mary's age and that of John, the representation of Mary's age is (X + 5).

Your question seems incomplete or not worded well so I'll give a more general response.

Mary is said to be older than John by 5 years. This means that however old John gets, Mary will always be older by 5 years.

If John is X years therefore, Mary's age will simply be:

= John's age + Age difference

= X + 5

For instance, if John is 20 years then Mary would be:

= 20 + 5

= 25 years

Find out more age related math problems at https://brainly.com/question/18915001.

#SPJ1

Answer: x = 74.3

Step-by-step explanation:

Let 22 be reference angle

so

tan 22 = p/b

tan 22 = 30/x

or, x= 30/tan22

so, x = 74.252

so, x = 74.3

Answer:

Step-by-step explanation:

tex]\tt{ \green{P} \orange{s} \red{y} \blue{x} \pink{c} \purple{h} \green{i} e}[/tex]

Answer:

Shorter leg is 7

Bigger leg is 7√3 = 12.1 (rounded to the nearest tenth)

As in the picture.hope it helps.......

Plzzzz mark brainlist if correct.....

Answer:

Học sinh nam là 21 học sinh, số học sinh nữ là 15 học sinhH

Step-by-step explanation:

Tỉ số giữa nam và nữ là x/y = 7/5 => x/7 = y/5

áp dụng tính chất của dãy tỉ số bằng nhau, ta được:  

x/7 = y/5 => x-y =/7-5 = 6/2 = 3

Vì x/7 = 3 => x = 21

y/5 = 3 => y= 15

Vậy số học sinh nam là 21 học sinh, số học sinh nữ là 15 học sinh

Answer:

B. $28

Step-by-step explanation:

Find the sales tax by finding 4% of 711:

711(0.04)

= 28.44

This is closest to 28.

So, the correct answer is B. $28

Answer:

ES LA NUME  C                                        R

Step-by-step explanation:

Answer:

( 1, - 3.5 )

Step-by-step explanation:

Given endpoints (x₁, y₁ ) and (x₂, y₂ ) the midpoint is

( [tex]\frac{x_{1}+x_{2} }{2}[/tex] , [tex]\frac{y_{1}+y_{2} }{2}[/tex] )

Here (x₁, y₁ ) = C (9, 2) and (x₂, y₂ ) = D (- 7, - 9 )

midpoint = ( [tex]\frac{9-7}{2}[/tex] , [tex]\frac{2-9}{2}[/tex] ) = ( [tex]\frac{2}{2}[/tex], [tex]\frac{-7}{2}[/tex] ) = (1, - 3.5 )

Answer:

selling prices =10% 10+150+15%=180

Answer:

Option 4. All real numbers greater than or equal to 2.

I hope this will help.

Answer: See explanation

Step-by-step explanation:

The question isn't complete. Here is the completed question that I got online.

Fifteen hundred (1500) randomly selected South Carolina kindergarten

students were observed on the first day of school to determine if they knew how to tie a shoe. Using this information, please identify the following: Population:

Sample:

Variable:

Sample Size:

Sample Space:

The variable is: (qualitative/quantitative)

If 40% of the observed students knew how to tie their shoes, how many of the 58,135 kindergarten students in SC can we expect to know how to tie their shoes?

Sample: The sample is 1500.

Variable: This is the number of students who know how to tie their shoes.

Sample Size: 1500

Sample Space: The total number of students in South Carolina kindergarten

The variable is quantitative since they're counted.

If 40% of the observed students knew how to tie their shoes, therefore the number from the 58,135 kindergarten students in SC that can be expected to know how to tie their shoes will be:

= 40% × 58135

= 0.4 × 58315

= 23254

Answer:

36: G-30

37: Please add the rest of the questions, so I can answer 37.

Step-by-step explanation: