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
Can someone help me with this math homework please!
Answers
Answer:
I believe its (-3,-2)...........
What are the domain and range of the inequality y < sqrt x+3+1
I don't get it I try to solve it but I just didn't get .
Answers
Given:
The inequality is:
[tex]y<\sqrt{x+3}+1[/tex]
To find:
The domain and range of the given inequality.
Solution:
We have,
[tex]y<\sqrt{x+3}+1[/tex]
The related equation is:
[tex]y=\sqrt{x+3}+1[/tex]
This equation is defined if:
[tex]x+3\geq 0[/tex]
[tex]x\geq -3[/tex]
In the given inequality, the sign of inequality is <, it means the points on the boundary line are not included in the solution set. Thus, -3 is not included in the domain.
So, the domain of the given inequality is x>-3.
We know that,
[tex]\sqrt{x+3}\geq 0[/tex]
[tex]\sqrt{x+3}+1\geq 0+1[/tex]
[tex]y\geq 1[/tex]
The points on the boundary line are not included in the solution set. Thus, 1 is not included in the range.
So, the domain of the given inequality is y>1.
Therefore, the correct option is A.
I’m pretty sure the answer is c but I need further help to understand if I am right or not
Answers
Answer:
you are correct'v'
Step-by-step explanation:
in the first column it adds the next odd number, 1, 3, 5,7
and in the 2nd it mutiplies by 2 so it would be faster by a whole lot
PLEASE HELP 30 POINTS
Find the value of x in the triangle below.
804
155
55°
o
75
80°
Ο Ο
85
Answers
Answer:
75°
Step-by-step explanation:
First, we need to know that the interior angle sum of a triangle is always 180°.
Now, to find the missing angle aside from x, we need to complete the sum 180-155=25, seeing 155° lies on a straight line. Remembering the interior angle sum of a triangle is always 180°, it is thus clear that 25+80+x=180. If we complete this equation, x=75.
Hope this helps!
HELP ASAP ILL GIVE BRAINLIST
Construct the equation of the graph given. Label the intercept and categorize this graph a horizontal or vertical line.
Answers
Answer:
Horizontal line
Step-by-step explanation:
uehdjd
Lisa runs 6 miles in 50 minutes. At the same rate, how many miles would she run in 35 minutes?
Answers
Answer:
6/50 = .12 m/min
.12 * 35 =4.2 miles
Step-by-step explanation:
In a bowl of fruit, there are green grapes and black grapes in the ratio 3 : 4
If there are 24 green grapes, how many black grapes are there?
Answers
Answer:
32
Step-by-step explanation:
Green : black
3 4
We have 24 green
3+8=24
so multiply each side by 8
Green : black
3*8 4*8
24 32
There are 32 black grapes
Answer:
32
Step-by-step explanation:
By Question :-
Green grapes: Black grapes= 3:4Let :-
Number of black grapes = xTherefore,
GG/ BG = 3/4 24/x = 3/4 x = 24 × 4/3x = 8 × 4x = 32Please help 33 points
Answers
Answer: it’s 111
Step-by-step explanation:
List the integers which satisfy the inequality 4.5< -X
Answers
There are an infinite number of them.
The ten greatest ones are -5, -6, -7, -8, -9, -10, -11, -12, -13, and -14 .
Now that I've given you ten of them, there are only an infinite number more. I'm too busy right now to list them all.
Answer:
p and q are two numbers.whrite down an expression of.
Please HELP! ):
The measure of an interior angle of a regular polygon is eight times the measure of one of its exterior angles. How many sides does the polygon have?
Answers
if i wanted to make a 40,000 payment in one year with a 5% annual interest rate, how much should i invest now?
Answers
Answer:
38,095.24
Step-by-step explanation:
40,000 = P(1 + 0.05)^1
P = 40,000/1.05
P = 38095.2380952
I need help what’s the answer I’m trying to pass?
Answers
Answer:
11.925
Step-by-step explanation:
Bryant bought 5 pounds of bananas for $3.45. If Mel bought 7 pounds of
bananas from the same market stand, how much did he pay?
Answers
Answer:
Here is your answer..
Hope it helps
Which expressions are equivalent to the equation below
Answers
Answer:
Polynomial Expression.
Step-by-step explanation:
Janes but a small clectric car and recorded the distance it waveled. The table below shows the distance waveled (nt during the st 4 seco
Bapsed Time Distance Traveled
(seconds) feet)
1
62
2
125
3
186
243
Which of the following equations represents the relationship between the distance traveled and the clapsed time?
Of=52-5
52-
+=52
52
Answers
Answer:
50
Step-by-step explanation:
Find the size of the angles marked by letters in the following diagram.
Answers
Answer:
x = 52
y = 19
Step-by-step explanation:
The degree measure of a straight line is (180) degrees. One can use this to find the measure of the angle that is adjacent to the angle with a measure of (142) degrees. Form an equation and solve for the unknown,
142 + (unknown angle) = 180
unknown angle = 38
The inscribed angle theorem states that twice the measure of an angle with its vertex of the circumference (outer edge) of a circle is equal to the measure of the surrounding arc. Therefore, one can state the following:
(2)(unknown angle) = (surrounding arc)
(2)(38) = (surrounding arc)
76 = surrounding arc
The central angles theorem states that the measure of an angle whose vertex is the center of the circle is equal to the measure of the surrounding arc. Therefore, one can state the following:
m<O = (surrounding arc)
m<O = 76
The radius is the distance from the center of the circle to the circumference of the circle. All radii in a circle are congrunet. Therefore the triangle with angle (x) and vertex (O) is an isosceles triangle, as two of its sides are radii, and are thus congruent. One property of an isosceles triangle is the base angles theorem. This theorem states that the angles opposite the congruent sides in an isosceles triangle are congruent. Moreover, the sum of angles in any triangle is (180) degrees. Therefore, one can make the following statement:
m<O + x + x = 180
76 + 2x = 180
x = 52
Finally, one can use the property that the sum of angles in any triangle is (180) degrees to make the following statement:
(x + 19) + (x + y) + (38) = 180
52 + 19 + 52 + y + 38 = 180
161 + y = 180
y = 19
x=52°
y=19°
Answer:
Solution given:
<OCA=19°[base angle of isosceles triangle]
Since ∆AOC is similar to ∆ BOC
y=19°[corresponding angle of a similar triangle are equal]
<OAB=<OBA=x[base angle of isosceles triangle]
again
<A+<B=180°[exterior angle of a triangle is equal to the sum of two opposite interior angle]
x+19+x+19=142°
2x=142°-38°
x=104/2
x=52°
0=(x-8)^2-100 Solve the problem using any type of way.
Answers
0 = (x-8)^2 -100
Add 100 to both sides
100 = (x-8)^2
Take the square root of both sides
10 = (x-8)
Remove the parentheses
10 = x-8
Add 8 to both sides
18 = x
Answer: x = 18
Tim has 17 marbles bob has 36 marbles and Jeffery has 49 marbles if they share all their marbles equally among themselves how many marbles will each boy get
Answers
PLS HELP PICS OF QUESTION ATTACHED!
Answers
Which number can each term of the equation be multiplied by to eliminate the fractions before solving ?
-3/4m - 1/2 = 2 + 1/4m
Answers
Answer:
4
Step-by-step explanation:
-3/4m - 1/2 = 2 + 1/4m
The denominators are 4 and 2
If we multiply by the least common multiply we can get rid of the fractions
2 and 4 have a least common multiple of 4
Drag the tiles to the correct boxes to complete the pairs.
Find the missing the coordinates.
(2, -2)
(-5, -5)
(2, 1)
(-1, -1)
A(-5, -1), B(1, -1), and C(1, -5) are
three vertices of rectangle ABCD. What
are the coordinates of vertex D?
arrowRight
A(2, 5), B(6, 5), and C(6, 1) are
three vertices of square ABCD. What are
the coordinates of vertex D?
arrowRight
A(2, 3), B(7, 3), and C(7, -2) are
three vertices of square ABCD. What are
the coordinates of vertex D?
arrowRight
A(-1, 4), B(7, 4), and C(7, -1) are
three vertices of rectangle ABCD. What
are the coordinates of vertex D?
arrowRight
Answers
Answer:
i think its 24
Step-by-step explanation:
2=2
The equation of the line is y =?
Answers
Answer:
y = -x/2 - 14
Step-by-step explanation:
Hint: The slope shows the rise over run, in this case, the slope is going 1 unit to the right and two units down.
Point A is a representation of which number on the number line?
A
B
D
-2
0
2
4
0 -3
0 1
T ♡rt
Answers
At an amusement park, 63 out of 70 tickets sold were discount tickets.
What percentage of the tickets were discount tickets?
Answers
Answer:
90%
Step-by-step explanation:
63/70 = 0.9 = 90%
Answer:
63 out of 70
63×10÷70=9
9%
Compute the standard deviation of the following set of data to the nearest whole number:
8, 12, 15, 17, 18
14
03
04
13
Answers
Answer:
Step-by-step explanation:
The standard deviation is the square root of the variance, and the variance is found by using the mean. So we will do that first. I will use the population variance as opposed to the sample variance since our set of numbers is small.
The mean: 8 + 12 + 15 + 17 + 18 = 70 and divide that by 5 to get
[tex]\bar{x}=14[/tex] and use this to find the variance in the formula:
[tex]s^2=\frac{\sum(x_i-\bar{x})^2}{n}[/tex] it is a bit difficult to enter that formula in correctly, but here's how it works mathematically:
[tex]s^2=\frac{(8-14)^2+(12-14)^2+(15-14)^2+(17-14)^2+(18-14)^2}{5}[/tex]
Squaring this ensures us that we don't end up with zero, which would be useless.
[tex]s^2=\frac{36+4+1+9+16}{5}[/tex] so
[tex]s^2=13.2[/tex] which means that the standard deviation is
s = 3.633
(If you do it with n-1 = 4 in the denominator of the variance, you get a standard deviation of 4.062)
What is the equation of the graphed line written in
standard form?
O x=-3
O y = -3
O x + y =-3
O X-y=-3
Answers
Answer:
Option A, x = -3
Step-by-step explanation:
Step 1: Find the graphed line
x = -3
Answer: Option A, x = -3
Which set of numbers does NOT represent the lengths of the sides of a triangle? A.) (7,5,6)
B.) (9,12,19)
C.) (7,18,11)
D.) (6,8,11)
Answers
Answer: B and C
Step-by-step explanation:
the triangle inequality theorem states that any 2 sides of a triangle must be greater than the measure of the third side. now with this rule, let's apply it to all options!
option a:
7 + 5 > 6 .. yes!
6+ 7 > 5 .. yes!
5 + 6 > 7 .. yes!
option b:
9 + 12 > 19 .. yes!
12 + 19 > 9 .. no!
19 + 9 > 12 .. no!
option c:
7 + 11 > 18 .. no!
11 + 18 > 7 .. no!
18 + 7 > 11 .. yes!
option d:
6 + 8 > 11 .. yes!
8 + 11 > 6 .. yes!
11 + 6 > 8 .. yes!
i did this topic years ago so please let me know if there are any mistakes! hope this helped, and good luck! ◝(ᵔᵕᵔ)◜
If x=(p-3) and y=(p+3),show that xy+9=psquare
Answers
Step-by-step explanation:
Answer with explanation is in the attachment
Hope it is helpful to you
the sum of three consecutive numbers is five times the difference of the middle number and 22. find the numbers.
Answers
Answer:
The numbers you're looking for are 54, 55, and 56.
Step-by-step explanation:
x + (x + 1) + (x + 2) = 5 * (x + 1 - 22)
3x + 3 = 5x - 105
3 = 2x - 105
108 = 2x
x = 54
x + 1 = 55
x + 2 = 56
13 Solve the inequality n+7<5n-8
Answers
Answer:
3.75 < n
Step-by-step explanation:
n + 7 < 5n - 8
Add 8 to both sides
n + 7 + 8 < 5n
n + 15 < 5n
Subtract 'n' from both sides
15 < 5n - n
15 < 4n
Divide both sides by 4
[tex]\frac{15}{4}[/tex] < n
3.75 < n
