find the value of angle BAC​

We will see that for the given vectors:

Remember that the dot product between two vectors:

a = (x₁, y₁) and b = (x₂, y₂) the dot product is:

a.b = x₁*x₂ + y₁*y₂ = |a|*|b|*cos(θ).

a) We have:

v = (3,-4) and w = (1,2)

The dot product will give:

v.w = 3*1 + (-4)*2 = 3 - 8 = -5

b) We will have:

|v|*|w|*cos(θ) = -5

Where:

Then we have:

5*√5*cos(θ) = -5

cos(θ) = -1/√5

θ = Acos(-1/√5) = 116.57°

The angle between the two vectors is 116.57°.

If you want to learn more about vectors, you can read:

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Answer:

2/7 + (-3/4) + (-2/7) + 4/3

If we look at 2/7 and (-2/7), we can see that both of them combined will get you a result of 0, so let's do that first.

2/7 + (-2/7) = 0

Now we're left with;

(-3/4) + 4/3

Make sure to convert both fractions into having a common denominator,

[They both have a common denominator of 12], so:

(-3/4) = (-9/12)

4/3 = 16/12

Add them:

(-9/12) + 16/12

16/12 - 9/12

= 7/12, which cannot further be simplified.

Answer:

-1.05

Step-by-step explanation:

Answer: 336ft²

Step-by-step explanation:

The polygon in the image provided is a trapezoid.

The formula for the area of a trapezoid is [tex]A=(\frac{a+b}{2} )(h)[/tex]

Where

A is the area

a is one of the bases (24 for this)

b is the other base (32 for this)

and h is the height (12 for this)

Sub the values into the formula and solve

[tex]A=(\frac{24+32}{2} )(12)\\A=(\frac{56}{2} )(12)\\A=(28)(12)\\A=336[/tex]

Answer:

336

Step-by-step explanation:

24 x 12 = 288. 12 x 8 = 96 divided by 2 is 48. 288 + 48 = 336

Answer:

2

Step-by-step explanation:

13+7x=27

-13 -13

7x=14

÷7

x=2

Answer:

x = 2

Step-by-step explanation:

Given

#1) Subtract 13 from each side.

#2) Divide 7 from each side.

Answer:

28.4

Step-by-step explanation:

10.5x2= 21

3.7x2= 7.4

21+7.4 = 28.4

Answer:

3/4

Step-by-step explanation:

two points are

(8,6) and (12,9)

formula :

(y2-y1)/(x2-x1)

(9-6)/(12-8) =

3/4

slope often means rate of change

in this graph

price changes as the number of lemon changes

in economics this graph is called the

supply curve

its called the law of supply

increases in price causes increase in the quantity supplied

if something is worth more, it will cause an increase in price which will cause people who want to make money to try supply more of it

quizlet

Answer:

perimeter is 36

Step-by-step explanation:

if x=3

then it turns into

Width 7-2(3)

length 5(3)+2

which equals

width 1

length 17

since it's a perimeter you add all four corners

which is 1+1+17+17=36

Answer:

2 inches

Step-by-step explanation:

if there are 2 books that are 1 1/2 thick, the second thinnest book would be 1/12... the second thickest book im guessing would be 3 1/2, so you'd have 2 inches in between

Answer: the answer is, 2 and one half

Step-by-step explanation: I took the test. Please give brainliest

Answer:

21482.20

Step-by-step explanation:

A = P(1+r/m)^mt

A = Total Amount, P = Principal, r = rate. m = number of months, t = time

24000 = P(1 + 0.037/12)^12*3

24000 = P(1.003083333)^36 --- I added 1  to 0.037 divied by 12, then multiplied 12*3 on the outside of the parentheses

24000 = 1.117204101(P)

24000/1,117204101 = 1.117204101P/1.1177204101

P = 21482.20

Good luck!  :)

Answer:

Step-by-step explanation:

[tex]\sf \dfrac{17}{3}x+17-\dfrac{2}{3}x-15 = \dfrac{17}{3}x-\dfrac{2}{3}x+17-15[/tex]

                               [tex]=\dfrac{17-2}{3}x + 2\\\\\\=\dfrac{15}{3}x+2[/tex]

The volume of a cuboid is the product of its length, width, and height. Out of the five statements B, C, and E are correct.

The volume of a cuboid is the product of its length, width, and height. It is formulated as:

[tex]\rm \text{Volume of Cuboid} = Length \times Width \times Height[/tex]

As the dimensions of the room are given and a room is mostly in the shape of a cuboid. Therefore, the volume of the room can be written as,

The volume of the room = 10ft × 15ft × 12ft = 1800 ft³

A.)

The heat produced by 3 people in a period of 9 hours will be

= 600 BTU × 3 people × 9 hour

= 16,200 BTU

We already know the volume of the room is 1800 ft³. Therefore, the heat produced per unit volume can be written as:

[tex]\rm \text{Heat produced per unit volume}= \dfrac{16,200\ BTU}{1800\ ft^3} = 9\ BTU/ft^3[/tex]

Hence, the statement that 3 people will produce approximately 8.33 BTUs/ft³ in a 9 hour period is wrong.

B.)

The heat produced by 4 people in a period of 10 hours will be

= 600 BTU × 4 people × 10 hours

= 24,000 BTU

We already know the volume of the room is 1800 ft³. Therefore, the heat produced per unit volume can be written as:

[tex]\rm \text{Heat produced per unit volume}= \dfrac{24,000\ BTU}{1800\ ft^3} = 13.334\ BTU/ft^3[/tex]

Hence, the statement that 4 people will produce approximately 13.334 BTUs/ft³ in a 10 hour period is correct.

C.)

The heat produced by 5 people in a period of 2 hours will be

= 600 BTU × 5 people × 2 hours

= 6,000 BTU

We already know the volume of the room is 1800 ft³. Therefore, the heat produced per unit volume can be written as:

[tex]\rm \text{Heat produced per unit volume}= \dfrac{6,000\ BTU}{1800\ ft^3} = 3.334\ BTU/ft^3[/tex]

Hence, the statement that 5 people will produce approximately 3.334 BTUs/ft³ in a 2 hour period is correct.

D.)

The heat produced by 6 people in a period of 4 hours will be

= 600 BTU × 6 people × 4 hours

= 14,400 BTU

We already know the volume of the room is 1800 ft³. Therefore, the heat produced per unit volume can be written as:

[tex]\rm \text{Heat produced per unit volume}= \dfrac{14,400\ BTU}{1800\ ft^3} = 8\ BTU/ft^3[/tex]

Hence, the statement that 6 people will produce approximately 7.334 BTUs/ft³ in a 4 hour period is wrong.

E.)

The heat produced by 7 people in a period of 4 hours will be

= 600 BTU × 7 people × 4 hours

= 16,800 BTU

We already know the volume of the room is 1800 ft³. Therefore, the heat produced per unit volume can be written as:

[tex]\rm \text{Heat produced per unit volume}= \dfrac{16,800\ BTU}{1800\ ft^3} = 9.334\ BTU/ft^3[/tex]

Hence, the statement that 7 people will produce approximately 9.334 BTUs/ft³ in a 4 hour period is correct.

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Answer(s)

Problem 9: 138.53

Problem 10: Function

Problem 11: Not A Function (Not Sure)

Edit; Problem 9 should've been right, I have no idea then.

Answer:

36,478 beads

Step-by-step explanation:

8723+4632+3512+5971=22,838

6,802+3,162+987+2,689=13,640

22,838+13,640= 36,478

So Cindy and Doris have 36,478 beads in total.

The proof of d^2y/dx^2 - 2 cot x dy/dx +3y = 0 is determined as 6cos²xsinx - 3sin³x - ​6cos²xsinx  + 3sin³x = 0

The equation is given as;

[tex]\frac{d^2y}{dx^2} - 2\ cotx \ \frac{dy}{dx} \ + 3y = 0 \ \ ---(1)[/tex]

y = sin³x

y = sin³x

let u = sinx  (du/dx = cosx)

y = u³

dy/du = 3u²

[tex]\frac{dy}{dx} = \frac{dy}{du} \ .\ \frac{du}{dx} \\\\[/tex]

dy/dx = 3u² x cosx

dy/dy = 3sin²xcosx

y' = 3sin²xcosx

y' = 3sin²xcosx

let u = sin²x  (du/dx = 2sinxcosx)

    v = cosx  (dv/dx = -sinx)

[tex]y'' = \frac{d^2y}{dx^2} = V\frac{du}{dx} + U\frac{dv}{dx}[/tex]

y'' = 3[cosx(2sinxcosx) + sin²x(-sinx)]

y'' = 6cos²xsinx  - 3sin³x

Substitute first derivative and second derivative of y in equation (1)

[tex]\frac{d^2y}{dx^2} - 2\ cotx \ \frac{dy}{dx} \ + 3y \\\\(6cos^2xsinx \ - \ 3sin^3x) \ - \ 2(\frac{cosx}{sinx} )(3sin^2xcosx) \ + 3(sin^3x) \\\\6cos^2xsinx \ - \ 3sin^3x \ - 6cos^2xsinx \ + \ 3sin^3x = 0 \ \ proved[/tex]

Learn more about differentiation here: https://brainly.com/question/25081524

Answer:

42

Step-by-step explanation:

Since each cut is 1/3 of a foot, you can tell that it will take 3 pieces to make 1 foot. Based on that ratio, you can do 14*3, which is 42 pieces.

Answer:

2x^2 + 3x - 7   (a= 2 , b= 3 , c= -7)

discriminant= b^2 - 4ac

                   = (3)^2 - 4(2)(-7)

                   = 9 + 56 = 65

The answer is D. 65

Hope this helps :)

7:obtuse angle

8:right angle

9:FDE, AFB

This answer was deemed incorrect, so sorry for posting this!

Answer:

chocolate chips: $3.75

walnuts: $2.5

Step-by-step explanation:

lets say chocolate chips cost x dollars and walnuts cost y dollars. we then have

6x + 5y = 35

2x + 3y = 15

multiply the second equation by 3 to get 6x + 9y = 45

subtract the 1st equation from the new equation to get 4y = 10, so y=$2.50

plug this value into the 2nd equation to get x=$3.75

Answer:

Problem 17

Independent -- T

dependent -- D

_________________________

Problem 16

Independent -- X

dependent -- Y

_________________________

Problem 18

Independent -- R

dependent -- Q

Step-by-step explanation:

Answer:

-5015

Step-by-step explanation:

Sum of a Geometric Series (finite)

Step 1 : Finding n

Step 2 : Substitute the values in the Sₙ formula

Answer:

1 and 20    or   2 and 10   or   4 and 5

Step-by-step explanation:

the divisors of 20 are 1 , 2 , 4 , 5 , 10 , 20

Then

20 = 1 × 20

     = 2 × 10

     = 4 × 5

Answer:

The answer should be 2

Step-by-step explanation:

P

r

=

n

!

(

n

−

r

)

!Subtract

1

from

2

.Simplify

2

!

(

1

)

!

.

Answer: the answer is 1 over 2 which is e

Step-by-step explanation: 4 and 2 and 3 equal 9 so 1 over 6 times 9 cubes equal 1.5 which is 1 over 2