Answer:
k = 3.
Step-by-step explanation:
At the given point x = -1 an f(x) = 1/2, so we have the equation:
1/2 = (2 - k)/(5(-1) + k)
(2 - k)/(k - 5) = 1/2
Cross multiplying:
2(2 - k) = k - 5
4 - 2k = k - 5
-2k - k = -5 -4
-3k = -9
k = 3.
Find cosθ+cos3θ+cos5θ+cos7θ by using the Sum-to-Product Formula.
Please also show your work as well. Thanks!
Answer:
[tex] \rm\displaystyle 4\cos( \theta) \cos \left( {2\theta} \right) \cos \left( {4 \theta } \right) [/tex]
Step-by-step explanation:
I assume the question want us to rewrite cosθ+cos3θ+cos5θ+cos7θ by using Sum-to-Product Formula and note that it's not an equation therefore θ can never be specified
===========================
so we want to rewrite cosθ+cos3θ+cos5θ+cos7θ by using Sum-to-Product Formula the good news is that the number of the function of the given expression is even so there's a way to do so, rewrite the expression in parentheses notation:
[tex] \rm\displaystyle \left( \cos( \theta) + \cos(3 \theta) \right) + \left(\cos(5 \theta) + \cos(7 \theta) \right)[/tex]
recall that,Sum-to-Product Formula of cos function:
[tex] \rm \boxed{\displaystyle \cos( \alpha ) + \cos( \beta ) = 2 \cos \left( \frac{ \alpha + \beta }{2} \right) \cos \left( \frac{ \alpha - \beta }{2} \right) }[/tex]
notice that we have two pair of function with which we can apply the formula thus do so,
[tex] \rm\displaystyle \left( 2\cos \left( \frac{ \theta + 3 \theta}{2} \right)\cos \left( \frac{ \theta - 3 \theta}{2} \right) \right) + \left(2\cos \left( \frac{5 \theta + 7 \theta}{2} \right) \cos \left( \frac{5 \theta - 7 \theta}{2} \right) \right)[/tex]
simplify addition:
[tex] \rm\displaystyle \left( 2\cos \left( \frac{4 \theta}{2} \right)\cos \left( \frac{ - 2\theta }{2} \right) \right) + \left(2\cos \left( \frac{12 \theta }{2} \right) \cos \left( \frac{ - 2 \theta}{2} \right) \right)[/tex]
simplify division:
[tex] \rm\displaystyle \left( 2\cos \left( {2 \theta} \right)\cos \left( { - \theta } \right) \right) + \left(2\cos \left( {6 \theta } \right) \cos \left( { - \theta} \right) \right)[/tex]
By Opposite Angle Identities we acquire:
[tex] \rm\displaystyle \left( 2\cos \left( {2 \theta} \right)\cos \left( { \theta } \right) \right) + \left(2\cos \left( {6 \theta } \right) \cos \left( { \theta} \right) \right)[/tex]
factor out 2cosθ:
[tex] \rm\displaystyle 2 \cos( \theta) (\cos \left( {2 \theta} \right) + \cos \left( {6 \theta } \right) )[/tex]
once again apply Sum-to-Product Formula which yields:
[tex] \rm\displaystyle 2 \cos( \theta) (2\cos \left( {4\theta} \right) \cos \left( {2 \theta } \right) )[/tex]
distribute:
[tex] \rm\displaystyle 4\cos( \theta) \cos \left( {2\theta} \right) \cos \left( {4 \theta } \right) [/tex]
and we're done!
What is the range of f(x)=4^x
Answer:
B
Step-by-step explanation:
At - infinity, the function will tend to 0 and at +infinity, the function will tend to +infinity. Those are the two extremas of the function and extremas define the range. Range is all positive real number
Can someone help me with this math homework please!
Answer:
f(n+1) = f(n) - 5
Step-by-step explanation:
Just find some relationship between 2 numbers that are next to each other.
Grandma is making a quilt. She has 540 cm of fabric to border the quilt. What is the greatest possible area for the quilt?
Question 1 options:
11 664 cm^2
18225 cm^2
72900 cm^2
291600 cm^2
Show your work:
Answer:
18225 cm²
Step-by-step explanation:
Divide 540 by 4 to get the length of all sides
540/4 = 135
Square 135 to get the max possible size
135² = 18225
18225 cm² is the greatest possible area for the quilt.
What is area?The measurement that expresses the size of a region on a plane or curved surface is called area. Surface area refers to the area of an open surface or the boundary of a three-dimensional object, whereas the area of a plane region or plane area refers to the area of a form or planar lamina.
Given
Divide 540 by 4 to obtain the length of all sides
540/4 = 135
Square 135 to acquire the max possible size
135² = 18225
18225 cm² is the greatest possible area for the quilt.
To learn more about area refer to:
https://brainly.com/question/25292087
#SPJ2
please help me its urgent
Answer:
number of students who like only iphone is 36...
Step-by-step explanation:
100 is the total number..
from that 40 like both so we subtract..
100-40=60..
60 = 2x + 3x..
60 / 5 = 12..
so numbet who like iphone is 3x which is 3 * 12=36..
Use the parabola tool to graph the quadratic function f(x)=−x2+4. Graph the parabola by first plotting its vertex and then plotting a second point on the parabola.
Answer:
see below
Step-by-step explanation:
f(x) = -x^2 +4
The vertex form is
y = a(x-h)^2 +k
Rewriting
f(x) = -(x-0)^2 +4
The vertex is (0,4) and a = -1
Since a is negative we know the parabola opens downward
f(x) = -(x^2 -4)
We can find the zeros
0 = -(x^2 -2^2)
This is the difference of squares
0 = -(x-2)(x+2)
Using the zero product property
x-2 =0 x+2 =0
x=2 x=-2
(2,0) (-2,0) are the zeros of the parabola and 2 other points on the parabola
We have the maximum ( vertex) and the zeros and know that it opens downward, we can graph the parabola
Answer:
Your vertex is (4,0)
Step-by-step explanation:
Find the length of the segment indicated. Round your answer to the nearest 10th if necessary.
Answer:
x=13.6
Step-by-step explanation:
By Pythagoras theorem, 5.5^2+x^2=14.7^2. x^2=14.7^2-5.5^2. x=13.6
If the speed of an object in motion is doubled, its kinetic energy becomes how many times the original kinetic energy
Answer: Becomes four times
Step-by-step explanation:
Given
Speed is doubled for a moving object
Suppose initial speed is u
Increased speed is 2u
Kinetic Energy is given by
[tex]\Rightarrow K=0.5mu^2[/tex]
When speed is doubled
[tex]\Rightarrow K'=0.5m(2u)^2\\\Rightarrow K'=(0.5mu^2)\times 4\\\Rightarrow K'=4K[/tex]
Kinetic energy becomes four times
Convert to decimal degrees.
-(167° 31”)
[?]°
Enter your answer with three decimal places.
Answer:
The angle in decimal form is 167.009°.
Step-by-step explanation:
We know an angle in terms of integer angles, minutes and seconds, whose conversion into decimal degrees is expressed by the following formula:
[tex]\theta = n + \frac{m}{60}+\frac{s}{3600}[/tex] (1)
Donde:
[tex]n[/tex] - Integer angle, in sexagesimal degrees.
[tex]m[/tex] - Minutes.
[tex]s[/tex] - Seconds.
If we know that [tex]n = 167[/tex], [tex]m = 0[/tex] and [tex]s = 31''[/tex], then the angle in decimal form is:
[tex]\theta = 167^{\circ}+\frac{0}{60}^{\circ} + \frac{31}{3600}^{\circ}[/tex]
[tex]\theta = 167.009^{\circ}[/tex]
The angle in decimal form is 167.009°.
Isabella runs 3 times per week. She ran for 15 minutes on Monday and 17 minutes on Wednesday. Her coach told her that she had run 80 percent of her goal that week. How many more minutes does she need to run to meet her goal for the week?
Answer
8 More minutes
Step-by-step explanation:
15+ 17 = 32
32/.8 = 40
40 - 32 = 8
use a double angle or half angle identity to find the exact value of each expression
Answer:
Step-by-step explanation:
There are 2 very distinct and important things that we need to know before completing the problem. First is that we are given that the cos of an angle is 1/3 (adjacent/hypotenuse) and it is in the first quadrant. We also need to know that the identity for sin2θ = 2sinθcosθ.
We already know cos θ = 1/3, so we need now find the sin θ. The sin ratio is the side opposite the angle over the hypotenuse, and the side we are missing is the side opposite the angle (we do not need to know the angle; it's irrelevant). Set up a right triangle in the first quadrant and label the base with a 1 (because the base is the side adjacent to the angle), and the hypotenuse with a 3. Find the third side using Pythagorean's Theorem:
[tex]3^2=1^2+y^2[/tex] which simplifies to
[tex]9=1+y^2[/tex] and
[tex]y^2=8[/tex] so
[tex]y=\sqrt{8}=2\sqrt{2}[/tex] so that's the missing side. Now we can easily determine that
[tex]sin\theta=\frac{2\sqrt{2} }{3}[/tex]
Now we have everything we need to fill in the identity for sin2θ:
[tex]2sin\theta cos\theta=2(\frac{2\sqrt{2} }{3})(\frac{1}{3})[/tex] and multiply all of that together to get
[tex]2sin\theta cos\theta=\frac{4\sqrt{2} }{9}[/tex]
A car travels 600 km in 6 hours. at what rate of speed is the car traveling?
Step-by-step explanation:
100Km/hours......V/T
Find the measure of the missing angle using the exterior angle sum theorm.
Answer:
95 degrees
Step-by-step explanation:
First find the angles within the triangle. 180 - 43 - 52 = 85, so the missing angle within the triangle is 85. The exterior angle would be supplementary to that, so 180 - 85 = 95.
H E L P !
Given that the Universal set is numbers 1 through 20, write the complement of the set A.
Set A : {1, 3, 7, 12, 14, 17, 19, 20}
Answer:
A' : {2, 4, 5, 6, 8, 9, 10, 11, 13, 15, 16, 18}
Aisha wants to paint the four walls of her living room.
Each wall is 2.2 m high and 5.5 m long.
One wall has a door of 1.8 m by 0.9 m.
Tins of paint cost £13 per 2 L tin.
Each litre of paint can cover 8 m2 of wall.
There is an offer of: Buy 2 tins get the 3rd at half price.
How much will Aisha pay to paint her living room?
Answer:
£32.50
Step-by-step explanation:
my first question to the teacher : so, no windows in the living room ?
so, it is a square living room with 5.5 m side length.
but each wall is a rectangle of 2.2 × 5.5 m.
for one wall we have to deduct a door area of 1.8×0.9 m.
so, one wall
2.2 × 5.5 = 12.1 m²
4 walls
4 × 12.1 = 48.4 m²
minus one door area
1.8 × 0.9 = 1.62 m²
48.4 - 1.62 = 46.78 m² total paint area
1 L paint covers 8 m².
so, we need 46.78/8 = 5.85 liters.
she gets the paint in 2 L tins. so, she needs 3 tins (6 L).
each tin costs £13.
and because she buys 3 tins, she gets the third one for half the price (13/2 = £6.50).
so, she has to pay
2×13 + 6.50 = 26 + 6.50 = £32.50
what is the cosine of 122.2
cosine 122.2 = -0.532876276......
Which table of values could be generated by the equation 10x+5y=15? (Will give brainlest and 21 points)
Answer:
(For the image) A
Step-by-step explanation:
Can someone help me with this math homework please!
Answer:
Second optionAs the x-values go to negative infinity, the function´s values go to positive. infinity.
--------------------------
Hope it helps...
have a great day!!
Answer:
(B) As the x-values go to negative infinity, the function's values go to positive infinity.
Step-by-step explanation:
The x-values the answer choices are talking about are the values on the x-axis.
Looking at the graph, when the x-values go to negative infinity (meaning it keeps on going left, or negative), the function goes up, meaning the function goes to positive infinity.
When the x-values go to positive infinity (meaning it keeps on going right, or positive), the function goes up, meaning the function goes to positive infinity.
Out of all the answer choices, only B agrees with the observations written above.
Hope that helps (●'◡'●)
A triangle has an area of 18ft squared. List all the possible positive integers that could represent its base and height. Use sentences to describe your process.
Answer:
1ft x 36ft
2ft x 18ft
3ft x 12ft
4ft x 9ft
6ft x 6ft
Step-by-step explanation:
A triangle is a three-sided polygon with three edges and three vertices. the sum of angles in a triangle is 180 degrees
Area of a triangle = 1/2 x base x height
If area is 18ft², then the dimensions of base x height = 18 x 2 = 36
all the possible positive integers that could represent its base and height can be determined be known by determining the factors of 36
factors of 36 = 1, 2, 3, 4, 6, 9, 12, 18, and 36
Possible dimensions of base and heights are :
1ft x 36ft
2ft x 18ft
3ft x 12ft
4ft x 9ft
6ft x 6ft
which of the following pairs of equations are perpendicular
Answer:
were are the pairs?
 The angle of elevation to a nearby tree from a point on the ground is measured to be 65°. How tall is the tree if the point on the ground is 92 feet from the tree? Round your answer to the nearest hundredth of a
foot if necessary.
Answer:
197.3 feet
Step-by-step explanation:
197.295 rounded to the nearest hundredth is 197.30 or 197.3
The height of the tree if the point on the ground from the tree is 92 feet will be 197.29 feet.
What is a right-angle triangle?It is a type of triangle in which one angle is 90 degrees and it follows the Pythagoras theorem and we can use the trigonometry function. The Pythagoras is the sum of the square of two sides is equal to the square of the longest side.
The angle of elevation to a nearby tree from a point on the ground is measured to be 65°.
The height of the tree if the point on the ground from the tree is 92 feet. Then we have
Let h be the height of the tree. Then we have
[tex]\tan 65^o = \dfrac{h}{92}\\\\ 2.1445\ = \dfrac{h}{92}[/tex]
Then we have
[tex]\rm h = 2.1445 \times 92\\\\h = 197.29\ ft[/tex]
More about the right-angle triangle link is given below.
https://brainly.com/question/3770177
The ratio of flour to water is 2 to 1 for biscuits Is Lisa has 4 cups of flour how much water should she add to make biscuits
Answer:
she should add 2 cups of water.
Step-by-step explanation:
2 : 1 = 4 : 2
Find the length of side BC give your answer to three significant figures
Answer:
19.4 cm
Step-by-step explanation:
Hi there!
This is a right triangle. We're given an angle, the side adjacent to the angle and we're solving for the hypotenuse. Given this information, we can use the cosine ratio:
[tex]cos\theta=\frac{adj}{hyp}[/tex]
Plug in the given angle and side
[tex]cos71=\frac{6.3}{BC}\\BC=\frac{6.3}{cos71} \\BC=19.4[/tex]
Therefore, the length of BC is 19.4 cm when rounded to 3 significant figures.
I hope this helps!
Three red balls, 5 green balls and a number of blue balls are put together in a sac. One ball is picked at random from the sac. If the probability of picking a red ball is 1|6, find the a) The number of blue balls in sac. B) the probability of picking a green ball
Answer:
total balls = 18 .... 3/x = 1/6
blue = 10 ... 18-(5+3) = 10
p of green = 5/18 = .277
Step-by-step explanation:
Find cos 0
A. 15/8
B. 15/17
C. 8/15
D. 8/17
Answer:
A.15/8
Step-by-step explanation:
the answer is 15/8
Answer:
D.
[tex]{ \tt{ \cos( \theta) = \frac{adjacent}{hypotenuse} }} \\ \\ { \tt{ \cos( \theta) = \frac{8}{ \sqrt{ {15}^{2} + {8}^{2} } } }} \\ \\ { \tt{ \cos( \theta) = \frac{8}{ \sqrt{289} } }} \\ \\ { \tt{ \cos( \theta) = \frac{8}{17} }}[/tex]
what is 3x10x178 I need help asap
Answer:
3x10=30 30x178=5,430
Step-by-step explanation:
[tex]3 \times 10 \times 178 \\ 30 \times 178 \\ 5340 \: \: answer[/tex]
What is the solution to this system of linear equations?
2%. + 3y = 3
7x-3y = 24
O (
27)
(3,-21)
O (3-1)
19.0
Answer:
(3,-1)
Step-by-step explanation:
2x + 3y = 3 -----------(I)
7x - 3y = 24 ----------(II)
Add equation (I) & (II) and y will be eliminated and we can find the value of 'x'
(I) 2x + 3y = 3
(II) 7x - 3y = 24 {Add}
9x = 27 {Divide both sides by 9}
x = 27/9
x = 3
Plugin x = 3 in equation (I)
2*3 + 3y = 3
6 + 3y = 3
Subtract 6 from both sides
3y = 3 - 6
3y = -3
Divide both sides by 3
y = -3/3
y = -1
Find f(-3) for f(x) = 4(2)^x
O A. -32
O B. 1/2
O C. -24
O D. 1/8
Answer:
B. 1/2
General Formulas and Concepts:
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightAlgebra I
Functions
Function NotationStep-by-step explanation:
Step 1: Define
Identify
f(x) = 4(2)ˣ
Step 2: Evaluate
Substitute in x [Function f(x)]: f(-3) = 4(2)⁻³Exponents: f(-3) = 4(1/8)Multiply: f(-3) = 1/2If f is continuous for all x, which of the following integrals necessarily have the same value?
Answer:
B
Step-by-step explanation:
Given the three integrals, we want to determine which integrals necessarily have the same value.
We can let the first integral be itself.
For the second integral, we can perform a u-substitution. Let u = x + a. Then:
[tex]\displaystyle du = dx[/tex]
Changing our limits of integration:
[tex]u_1=(0)+a=a \text{ and } u_2 = (b+a)+a = b+2a[/tex]
Thus, the second integral becomes:
[tex]\displaystyle \int_{0}^{b+a}f(x+a)\, dx = \int_a^{b+2a} f(u)\, du[/tex]
For the third integral, we can also perform a u-substitution. Let u = x + c. Then:
[tex]\displaystyle du = dx[/tex]
And changing our limits of integration:
[tex]\displaystyle u_1=(a-c)+c=a \text{ and } u_2=(b-c)+c=b[/tex]
Thus, our third integral becomes:
[tex]\displaystyle \int_{a-c}^{b-c}f(x+c)\, dx = \int_{a}^{b} f(u)\, du[/tex]
Since the only difference between f(x) and f(u) is the variable and both the first and third integral have the same limits of integration, our answer is B.
A square has a side length of 36 feet. This square is dilated by a scale factor of 2/3 to create a new square. What is the side length of the new square?
Answer:
24
Step-by-step explanation:
Multiply the side length by the dilation
36 x 2/3
72/3
Simplify
72/3 = 24
Your answer is correct