Let the lengths of each side of △ABC having area equal to 1 be as follows: AB = 2, BC = a and CA = b. Let CD be a perpendicular line from point C to AB. Answer the following questions.
(1) Given AD = x, write a²+(2√3-1)b² in the form of x.
(2) Find the value of x at which a²+(2√3 - 1)b² is the lowest and the magnitude of ∠BAC.
Need help! Please show your work too. Thanks!
Answers
Answer:
Part 1)
[tex]\displaystyle \left((2-x)^2 + 1)\right) + (2\sqrt{3} - 1 ) \left(x^2 + 1\right)[/tex]
Or simplified:
[tex]\displaystyle = 2\sqrt{3}x^2 - 4x + 4 + 2\sqrt{3}[/tex]
Part 2)
The value of x for which the given expression will be the lowest is:
[tex]\displaystyle x = \frac{\sqrt{3}}{3}\approx 0.5774[/tex]
And the magnitude of ∠BAC is 60°.
Step-by-step explanation:
We are given a ΔABC with an area of one. We are also given that AB = 2, BC = a, and CA = b. CD is a perpendicular line from C to AB.
Please refer to the diagram below.
Part 1)
Since we know that the area of the triangle is one:
[tex]\displaystyle \frac{1}{2} (2)(CD) = 1[/tex]
Simplify:
[tex]\displaystyle CD = 1[/tex]
From the Pythagorean Theorem:
[tex]\displaystyle x^2 + CD^2 = b^2[/tex]
Substitute:
[tex]x^2 + 1 = b^2[/tex]
BD will simply be (2 - x). From the Pythagorean Theorem:
[tex]\displaystyle (2-x)^2 + CD^2 = a^2[/tex]
Substitute:
[tex]\displaystyle (2-x)^2+ 1 = a^2[/tex]
We have the expression:
[tex]\displaystyle a^2 + (2\sqrt{3} - 1) b^2[/tex]
Substitute:
[tex]\displaystyle = \boxed{\left((2-x)^2 + 1)\right) + (2\sqrt{3} - 1 ) \left(x^2 + 1\right)}[/tex]
Part 2)
We can simplify the expression. Expand and distribute:
[tex]\displaystyle (4 - 4x + x^2 + 1)+ (2\sqrt{3} -1)x^2 + 2\sqrt{3} - 1[/tex]
Simplify:
[tex]\displaystyle = ((2\sqrt{3} -1 )x^2 + x^2) + (-4x) + (4+1-1+2\sqrt{3})[/tex]
Simplify:
[tex]\displaystyle = 2\sqrt{3}x^2 - 4x + 4 + 2\sqrt{3}[/tex]
Since this is a quadratic with a positive leading coefficient, it will have a minimum value. Recall that the minimum value of a quadratic always occur at its vertex. The vertex is given by the formulas:
[tex]\displaystyle \text{Vertex} = \left(-\frac{b}{2a}, f\left(-\frac{b}{2a}\right)\right)[/tex]
In this case, a = 2√3, b = -4, and c = (4 + 2√3).
Therefore, the x-coordinate of the vertex is:
[tex]\displaystyle x = -\frac{(-4)}{2(2\sqrt{3})} = \frac{1}{\sqrt{3}} =\boxed{ \frac{\sqrt{3}}{3}}[/tex]
Hence, the value of x at which our expression will be the lowest is at √3/3.
To find ∠BAC, we can use the tangent ratio. Recall that:
[tex]\displaystyle \tan \theta = \frac{\text{opposite}}{\text{adjacent}}[/tex]
Substitute:
[tex]\displaystyle \tan \angle BAC = \frac{CD}{x}[/tex]
Substitute:
[tex]\displaystyle \tan \angle BAC = \frac{1}{\dfrac{\sqrt{3}}{3}} = \sqrt{3}[/tex]
Therefore:
[tex]\displaystyle\boxed{ m\angle BAC = \arctan\sqrt{3} = 60^\circ}[/tex]
Related Questions
HELPPP HELP PLS PRONTO ASAP
Ahmed is working at a restaurant. His boss pays him $16.00 per hour and
promises a raise of $1.25 per hour every 6 months. Which sequence
describes Ahmed's expected hourly wages, in dollars, starting with his current
wage?
Answers
Answer:
B
Step-by-step explanation:
each of the numbers is just adding 1.25 on to it
Answer: Choice B
16.00, 17.25, 18.50, 19.75, ...
==========================================================
Explanation:
We start with $16.00 as the first term, as this is the amount the boss pays him initially. Then we add on 1.25 to get 16+1.25 = 17.25 to represent the next wage after that first raise.
Then after the second raise he gets, he'll then earn 17.25+1.25 = 18.50 an hour. This process theoretically can go on forever, but realistically the boss will likely set some kind of limit.
We say that this sequence { 16.00, 17.25, 18.50, 19.75, ... } is arithmetic with the first term of 16.00 and common difference 1.25
The common difference is the gap width between any two neighboring terms, and it's the amount the wage goes up each time he gets a raise.
Given m
11
n, find the value of x and y.
41°
וז.
20
n
yº
So I keep getting the wrong answer could someone help me pls
Answers
Answer:
x = 41°, y = 139°
Step-by-step explanation:
The given parameters are;
Line m is parallel to line n and lines m and n have a common transversal
The corresponding angles formed by the common transversal to the two parallel lines are 41° on line m and x° on line n
Therefore, x° = 41° by corresponding angles formed between on two parallel lines by a common transversal are equal
x° and y° are linear pair angles and they are, supplementary
∴ x° + y° = 180°
∴ x° + y° = 41° + y° = 180°
y° = 180° - 41° = 139°
y° = 139°.
23. (04.05)
Which statement best describes the effect of replacing the function f(x) = 2 ^x-2 with the function g(x) = 2 ^x+3
The graph shifts 1 units left.
The graph shifts 5 units left.
The graph shifts 1 unit right.
The graph shifts 3 units right.
Answers
Answer:
The graph shifts 5 units left
Step-by-step explanation:
The given functions are;
f(x) = [tex]2^{x - 2}[/tex], g(x) = [tex]2^{x + 3}[/tex]
Therefore, we have;
When x = 2, f(2) = [tex]2^{2 - 2}[/tex] = 1 and g(2) = [tex]2^{2 + 3}[/tex] = 32
When x = 3, f(3) = [tex]2^{3 - 2}[/tex] = 2 and g(3) = [tex]2^{3 + 3}[/tex] = 64
When x = 6, f(6) = [tex]2^{6 - 2}[/tex] = 16 and g(6) = [tex]2^{6 + 3}[/tex] = 512
When x = 7, f(7) = [tex]2^{7 - 2}[/tex] = 32 and g(7) = [tex]2^{7 + 3}[/tex] = 1024
When x = 8, f(8) = [tex]2^{8 - 2}[/tex] = 64 and g(8) = [tex]2^{8 + 3}[/tex] = 2,048
Therefore, the y-value of f(x) obtained at x = 8, is obtained by g(x) at x = 3, and the graph is shifts(ed) 5 units left.
Help fast pleaseeeeeeee
Answers
Step-by-step explanation:
-2. = [tex] \frac{1}{49} [/tex]-1 = [tex] \frac{1}{7} [/tex]0 = 11. = 72. = 49The times to pop a 3.4-ounce bag of microwave popcorn without burning it are Normally distributed with a mean
time of 140 seconds and a standard deviation of 20 seconds. A random sample of four bags is selected and the
mean time to pop the bags is recorded. Which of the following describes the sampling distribution of all possible
samples of size four?
Answers
This question is solved using the central limit theorem, giving an answer of:
Fourth option, approximately normal with mean of 140 seconds and standard deviation of 10 seconds.
Central Limit Theorem
The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
Mean of 140, standard deviation of 20, sample of 4:
By the Central Limit Theorem, the distribution is approximately normal.
Mean is the same, of 140.
[tex]n = 4, \sigma = 20[/tex], thus:
[tex]s = \frac{\sigma}{\sqrt{n}} = \frac{20}{\sqrt{4}} = 10[/tex]
Thus, the correct answer is:
Fourth option, approximately normal with mean of 140 seconds and standard deviation of 10 seconds.
For another example of the Central Limit Theorem, you can check https://brainly.com/question/15519207
Colin is painting figurines. He spends 20 minutes painting each figurine. After painting for 60 minutes, he still has 9 more figurines left to paint.
Answers
Answer:
9 times 20 is equally to 180 minutes
Answer:
f=-1/20t+12
Step-by-step explanation:
khan
Which number sentence is not true?
A. |-20| < 20
B. |9| = 9
C. |-20| > |9|
D. |9| < |20|
Answers
|x| basically means the count of how far from zero. It will always be a positive number.
So the answer is A. |-20| < 20
because 20 is not greater than 20
factor and solve the problem in the photo ……. pleaseeee helppppp i havent done algebra in 2 years
Answers
Answer:
Not factarable, all terms must be in x. or y
Step-by-step explanation:
Find the measure of <3. 90 50 40 130
Answers
=============================================================
Explanation:
This figure is a kite since we have two pairs of adjacent sides that are congruent, but not all sides are the same length.
One property of kites is that the diagonals are always perpendicular (this applies to rhombuses as well). This means angle 3 is 90 degrees.
The measure of ∠3 is 90°
Because in a kite the diagonals bisects at 90°
Therefore ∠3 is 90°
Answered by Gauthmath must click thanks and mark brainliest
Which value of x makes this equation true?-9x+15=3(2-x)
Answers
Step-by-step explanation:
-9x+15=3(2-x)
expand the bracket by the right hand side6-6x
2. collect like terms
-9x+15= 6-6x
15-6 = 6x+9x
11= 15x
3. divide both sides by the coefficient of X which is 15
x= 11/15
What is the value of x?
Answers
Answer:
x=5
Step-by-step explanation:
[tex]\frac{10}{x} = \frac{4x}{10}[/tex]
[tex]4x^{2} =100\\x^{2} =25\\x=5[/tex]
find the shaded area...
Answers
Answer:
148°
Step-by-step explanation:
The central angle is twice the angle at the circumference, subtended on the same arc.
shaded angle = 2 × 74° = 148°
What is the solution of x + 1/5 (x - 1) = 1?
Answers
Answer:
1
Step-by-step explanation:
x-1+ 1 /5*( x-1)=0
(x-1)*6/5=0
x=1
what is the CP if SP is Rs:20 and profit is Rs:7
Answers
Answer:
CP is 13 because 20-13=7 also you can subtract 20-7=13
So, here us your ans 13.
Can some one help please
Answers
Answer: [tex]\fbox{C} \: \: \: \dfrac{4 \times 10^{4} }{3 \times 10^{4} }[/tex]
Step-by-step explanation:
36,070 = 3.607 · 10⁴ ≈ 4 · 10⁴
29,029 = 2.9029 · 10⁴ ≈ 3 · 10⁴
Let's how manytimes greater the distance to the bottom of Challenger Deep is than the distance to the top of Mount Everest:
[tex]\dfrac{4 \times 10^{4} }{3 \times 10^{4} }[/tex]
Answer:
C
Step-by-step explanation:
First, the question is asking how many times greater the distance to the Challenger Deep is compared to Mount Everest. This means that the Challenger Deep will be on top, with the distance to Mount Everest on the bottom.
Next, we can see that in our answers, we are only given one significant digit. This means that we have to round our original numbers to the nearest significant digit and work from there. For Challenger Deep, 36,070 must be rounded to the nearest ten thousandth as it is in the ten thousands. Therefore, it must be rounded to 40,000 or 30,000. As 36,070 is closer to 40,000 than 30,000 (we can tell this because the second number, 6, is greater than 5, so we round up), we can represent this as 40,000. For Mount Everest, we can round 29,029 to either 20,000 or 30,000. 30,000 is the appropriate choice here because 9, the second number, is greater than 5.
Therefore, our ratio is now 40,000 / 30,000 . Our answers are written in scientific notation, so we must convert our numbers to those values.
Let's start with 40,000 . Our one significant digit is 4, so we can write this as 4 * something. For each number in 10 to the power of x (x is a placeholder value), we add x amount of zeros. For example, for 4 * 10², we add 2 zeros, making it 400. There are 4 zeros here, so to write this in scientific notation, we have 4 * 10^4
Similarly, for 30,000 , we can write this as 3 * 10^4 as there are 4 zeros.
Our ratio is thus 40,000 = 4*10^4 , which is the Challenger Deep value rounded, over 30,000 = 3 * 10^4, which is the Mount Everest value rounded. We can write this as [tex]\frac{4*10^{4}}{3*10^{4}}[/tex], or C
Help me with this anyone
Answers
Answer:
1/4
Step-by-step explanation:
b+-sqrt b^2-4ac all over 2a
Find the midpoint of AC.
Answers
Answer:
(0+a)/2 , (0+a)/2
= (a/2, a/2)
Answered by GAUTHMATH
Find the area of the shaded region
Answers
Answer: Ssh=1323π
Step-by-step explanation:
The point O Centre big circle r1=2r2=4 then radius small cirler r2=21Then S1=42²π=1764 ; S2=21²π=441 π S(shaded)=S1-S2=?Ssh=(1764-441)π=1323πThe equation of a line is y = 2x + 3. What is the equation of the line that is parallel to the first line and passes through (2, –1)?
A.
4x – 2y = –6
B.
y = 2x – 5
C.
y = 3x + 4
D.
2x + y = –1
Answers
Answer:
i think the answer is y = 3x + 4
Step-by-step explanation:
:)
I need help with this please :)
Answers
Answer:
C
Step-by-step explanation:
this is an arithmetic sequence (we add something from element to element).
"an" describes the salary during the nth year.
a1 = $3000
a2 = a1 + 600
a3 = a2 + 600 = a1 + 600 + 600 = a1 + (3-1)×600
an = a1 + (n-1)×600 = 3000 + (n-1)×600
so,
a15 = 3000 + (15-1)×600 = 3000 + 14×600 = $11400
PLZZZ HELPPP, IF NOT 100% SURE PLZ DONT ANSWER…BRAINLIEST TO FIRST AND CORRECT ANSWER, THX TO SECOND AND CORRECT ANSWER
Answers
9/16
EXPLANATION
9/8 divided by 2/1
=
9 x 1
8 x 2
=
9/16
given a sphere with a radius of m. what is the locus of the midpoints of the radii of the sphere?
Answers
Answer:
The locus of the midpoints of the radii of the sphere is a sphere half the radii M of the given sphere and having the same center as of the given sphere.
Step-by-step explanation:
What is the slope of the line whose equation is y = –2x – 5?
Answers
Answer:
Slope = -2
Step-by-step explanation:
The coefficient next to x is indicative of the equation's slope.
Answer:
slope = gradient
straight line equation is y = mx + c
where m is gradient therefore answer is -2
Consider the first month's sales data for the Midwest region.
Select the correct answer from each drop-down menu.
1. 85
2. 15
3. 37
4. 18
1. Significantly different from
2. Relatively close to
1. inconsistent
2. consistent
Answers
Answer:
The correct options are:
1. Significantly different from
1. Inconsistent
Explanation:
Sales Data for Midwest:
Midwest region total stores Sales equal to 63.1%. The percentage for current store is less than total stores therefore data in the given table is not consistent. The data given is relatively for the first month sales and is significantly different from the other stores.
Answer:
In the picture
Step-by-step explanation:
From Plato / Edm
6. How much larger is 2 x 104 than 8 x 102?
A. 15
B. 20
C. 25
D. 30
Answers
Answer:
20
Step-by-step explanation:
it is 20
Two friends are writing practice problems to study for a trigonometry test. Sam writes the following problem for his friend Anna to solve:
In right triangle ABC, the measure of angle C is 90 degrees, and the length of side c is 8 inches.
Solve the triangle.
Anna tells Sam that the triangle cannot be solved. Sam says that she is wrong.
Who is right? Explain your thinking
Answers
Answer:
Anna is right in her meaning concerning on triangle solvability.
Step-by-step explanation:
The side [tex]c[/tex] represents the hypotenuse of a right triangle as [tex]C = 90^{\circ}[/tex] and is opposite to that angle. There are two ways to solve this triangle trigonometrically:
i) Law of Sine
[tex]\frac{a}{\sin A} = \frac{b}{\sin B} = \frac{c}{\sin C}[/tex] (1)
ii) Law of Cosine
[tex]c^{2} = a^{2} + b^{2} - 2\cdot a\cdot b \cdot \cos C[/tex] (2)
The Pythagorean Theorem is a particular case of the Law of Cosine for [tex]C = 90^{\circ}[/tex]
The triangle cannot be solved as there is an input missing, either another side or another angle. If [tex]C = 90^{\circ}[/tex], then (2) is reduced into this form:
[tex]c^{2} = a^{2}+b^{2}[/tex] (2b)
In this case we need to know the measure of either [tex]a[/tex] or [tex]b[/tex] to determine its counterpart and the values of the missing angles by (1). In nutshell, Anna is right.
When -2(x − 4) + 1 = 7 is solved, the result is:
Answers
Answer:
1
Step-by-step explanation:
-2(x-4)+1=7
First Distribute the -2.
-2x+8+1=7
Subtract the 8 and 1 from the whole equation.
-2x=-2
Divide both sides of the equation by -2.
x=1
I hope this helps!
Answer:
x = 1
Step-by-step explanation:
-2(x − 4) + 1 = 7
-2x + 8 + 1 = 7
-2x + 9 = 7
-2x = -2
x = 1
which of the following is a result of shiftinga circle with equation (×-2)+(y-3)^2= 25 to the left 2 unit ?
Answers
Answer:
x^2+(y-1)^2=25
Step-by-step explanation:
eqn of circle : (x-h)^2+(y-k)^2=r^2
center of circle = (h,k)
hence, the center of the current circle is (2,3)
moving 2 units to the left would make the center (0,1)
the radius would remain the same (5) , hence the new eqn would be
(x-0)^2+(y-1)^2=25
x^2+(y-1)^2=25
The denominator of a fraction is 5 more than the numerator. if both the numerator and denominator are increased by 3, the the resulting fraction becomes 3/4. find the original fraction.
Answers
Answer:
12/17
Step-by-step explanation:
Let
Numerator of the fraction = x
Denominator of the fraction = x + 5
The fraction is
x / (x + 5)
if both the numerator and denominator are increased by 3, the the resulting fraction becomes 3/4.
x + 3 / (x + 5) + 3 = 3/4
x + 3 / x + 8 = 3/4
Cross multiply
(x + 3)4 = (x + 8)3
4x + 12 = 3x + 24
4x - 3x = 24 - 12
x = 12
Recall,
x / (x + 5)
= 12 / (12 + 5)
= 12/17
The original equation = 12/17
Can someone find this for me please?
Answers
Answer:
the larger one is 183
Step-by-step explanation:
[tex]x + y = 262 \\ x - y = 104 \\ y = 262 - x \\ x - (262 - x) = 104 \\ x - 262 + x = 104 \\ 2x = 104 + 262 \\ 2x = 366 \\ x = 183 \\ y = 262 - 183 \\ y = 79[/tex]
