prove that:
cos20°cos40°cos80°=1/8
Answers
Answer:
see explanation
Step-by-step explanation:
Using the double angle identity for sine
sin2x = 2sinxcosx
Consider left side
cos20°cos40°cos80°
= [tex]\frac{1}{2sin20}[/tex] (2sin20°cos20°)cos40°cos80°
= [tex]\frac{1}{4sin20}[/tex] (2sin40°cos40°)cos80°
= [tex]\frac{1}{4sin20}[/tex] (sin80°cos80° )
= [tex]\frac{1}{8sin20}[/tex] (2sin80°cos80° )
= [tex]\frac{1}{8sin20}[/tex] . sin160°
= [tex]\frac{1}{8sin20}[/tex] . sin(180 - 20)°
= [tex]\frac{1}{8sin20}[/tex] . sin20°
= [tex]\frac{1}{8}[/tex] = right side , thus proven
Step-by-step explanation:
hope its helps you have a great day keep smiling be happy stay safe ☺
Related Questions
Parallel lines m and n are cut by transversal t. Identify if the Pair of angles are vertical or not
vertical.
∠1 and ∠4
A. Vertical
B. Not Vertical
Answers
Yada yada yada
Solve x TN = 8 nV =x - 2?
Answers
Answer:
10
Step-by-step explanation:
STUV is a parallelogram.
TV and SU are its diagonals intersecting at point N.
Diagonals of a parallelogram bisects each other.
Therefore, TN = NV
8 = x - 2
8 + 2 = x
10 = x
x = 10
Allen is 5 years older than Cassandra. In 4 years, he will be twice as old as Cassandra was 2 years ago. Find their ages.
Answers
Answer:
C = 13, A = 18
Step-by-step explanation:
A = 5 + C
A + 4 = 2(c-2)
5+c+4 = 2c - 4
9 + c = 2c - 4
c = 2c - 13
-1c = -13
c = 13
A = 5 + 13
A = 18
Which expression is equivalent ?
Answers
Answer:
D
Step-by-step explanation:
When you do a power to a power you multiply
4 * 2/9 = 8/9
Answer:
12^8/9
Step-by-step explanation:
Someone please help me calculate the volume of these shapes
Answers
Answer:
A. 360 m ^2
B. 4021.2386 cm ^3
Step-by-step explanation:
A. V = w X h X l = 8 X 9 X 5 = 360 m ^3
B. V = πr2h = π·82·20 = 4021.2386 cm ^3
I hope that helps!! XD
help me pleasee i need help this is my final btw
Answers
Answer:
12 sq units
Step-by-step explanation:
height = 3
length = 4
A = l · w
A = 12
There are 40×5^7 chicken spread across 16×5^5 square miles of land on average number of chickens per square mile Round your answer to the nearest whole number
Answers
Answer:
63 chickens per square mile
Step-by-step explanation:
We are to calculate the average number of chickens per square mile.
Number of chickens = 40×5⁷
Number of square miles = 16×5⁵
The average number of chickens per square mile = 40 × 5⁷/16 × 5⁵
= 3125000/50000
= 62.5 chickens per square mile
Approximately to the nearest whole number is
= 63 chickens per square mile
Therefore,the average number of chickens per square mile is 63 chickens per square mile.
Easy 3rd grade mathy! ITS 100 POINTS
Answers
Answer:
3.5?
Step-by-step explanation:
May I have brainliest please I'm trying to level up!
</3 PureBeauty
Answer:
uhmm 3.2???
Step-by-step explanation:
I barely remember not gonna lie :'(
(01.05)
What is the equation, in slope-intercept form, of the line that passes through (0, -2)
and has a slope of -3? (5 points)
O 1) y = -3x - 2
O 2 y=-3x+ 2
O3) y = –2x+3
O 4) y = -2x - 3
Answers
Answer:
O1
Step-by-step explanation:
Slope intercept form is y=mx+b, where m is the slope and b is the y intercept.
We are given a point: (0,-2) and a slope; -3.
we can substitute the numbers into the equation above, with what we know, to find b.
-2=-3(0)+b
multiply
-2=0+b
-2=b
so the y intercept is -2.
Since we know that the slope is -3, and the y intercept is -2, the equation is y=-3x-2
Therefore O1 is your answer
Hope this helps!
Jupiter,Saturn or Uranus?
Answers
Answer:
Jupiter :)
Step-by-step explanation:
An online company clothing company sells custom sweatshirts. The company charges $6.50 for each sweatshirt and a flat fee of $3.99 for shipping. Write a linear function in the form `y=mx+b`that represents the total cost, y, in dollars, for a single order of x sweatshirts.
Answers
Answer:
y = 6.5x + 3.99
Step-by-step explanation:
Let
Total cost = y
Single order of sweatshirts = x
Each sweat shirt = $6.50
We are given the linear function =
y = mx + b
Hence:
y = $6.50 × x + $3.99
y = 6.5x + 3.99
Therefore, the linear function in the form y=mx+b that represents the total cost is given as:
y = 6.5x + 3.99
Write 5.164 x 10^-4 in standard form.*
Answers
Answer is 0.0005164x
The difference between three times a number and eight equals negative five. What is the number?
6.3
-4.3
-1
1
Answers
Answer:
it's 1
Step-by-step explanation:
when one is multiplied by three times.it gives us three and its difference result negative five 3–8 = -5
Find the values of v, w, x, y and z
Answers
Y= 180-90-35 = 55
V= 90-55 = 35
W= 180-90-35 = 55
Z= 90-55 = 35
Help Please! △ABC is given with line m drawn through A parallel to BC¯¯¯¯¯¯¯¯. In the course of proving that the interior angle measures of △ABC sum to 180°, which of the following will be shown? Select the two correct answers.
∠1≅∠B
∠1≅∠C
m∠1+m∠BAC+m∠2=180°
m∠BAC+m∠C+m∠2=180°
∠2≅∠A
Answers
not sure but i thibj the second one
Evaluate the expression.
(-5)(5) +5=
Answers
Answer:
Step-by-step explanation:
Here you go mate
Step 1
(-5)(5) +5 Equation
Step 2
(-5)(5) +5 Simplify
(-5)(5) +5
Step 3
(-5)(5) +5 Add and multiply them
(-25)+5
answer
-20
Determine the solution to the system of equations:
2y - 2x = 22
y = -4x + 1
Answers
Answer: Solve for the first variable in one of the equations, then substitute the result into the other equation.
Point Form:(-2,9)
Equation form: x=-2 y=9
Step-by-step explanation:
Point Form:(-2,9)
Equation form: x=-2 y=9
Write the ratio in simplest form.
The ratio of green beads : total number of beads is ???
Answers
Answer:
3:15
Step-by-step explanation:
£1 = $1.5 dollars
Convert £20 into dollars
Answers
Answer:
$30
Step-by-step explanation:
1.5 x 20 = 30
Q1: Fill in the blanks:
a) The number 3.23 can be expressed as fraction
Answers
Answer:
yes, as 3 23/100
Step-by-step explanation:
because
Answer:
I think it could be 3 23/100
Step-by-step explanation:
if Diana has three times more than her mother and her mother has 88 piles of clothes how many clothes does diana have? brainliest will be given out
Answers
Answer:
The answer would be 264 :)
Step-by-step explanation:
The distance between Dallas, TX and Houston, TX is 384 kilometers. There are approximately 8 kilometers in 5 miles. Which measurement is closest to the number of miles between these two cities?
Answers
Graph the following
y−2=2/3(x+4)
Answers
4.5m is__% of 90cm. And 90cm is ___% of 4.5m.
Pls help me! This is really hard.
Answers
1 meter is 100 centimeters (deci is 10, centi is 100, milli is 1000)
4.5 meter = 4.5 x 100 or 450 centimeters
(450/90)x100= 500%. 4.5 meters is 5 times longer than 90 cm
Cross check: 5x90=450
(90/450)x100= 20%
Cross check: .2x450=90
This has been answered before on Brainly
4.5m is 500% of 90cm
90cm is 20% of 4.5m.
Please help me with this..
Answers
So what is the answer to The spinner below is spun twice. What is the probability of the arrow landing on a 3 and then on an odd number?
Answers
Answer: nijja what
Step-by-step explanation:
Answer:
1/3
Step-by-step explanation:
6x^3 -x^2-10x-3 by 2x-3
Answers
Answer:
Quotient : 3x² + 5x + 1
Step-by-step explanation:
please help im so lost lol
Answers
Answer:
B, C, and E
Step-by-step explanation:
6(x+4)+35
B) 6x+ 6(4)+ 35 (They just distributed the 6 to the x but left the 4 undistributed)
C) 35+6(x+4) (If addition or subtraction, moving the numbers won't change the sum/difference)
E) 6(4+x)+35 (If addition or subtraction, moving the numbers won't change the sum/difference)
Answer:
I Honestly Dont Know Sorry haahahhahaha Go F ur self
Step-by-step explanation:
Which statement is true ?
Answers
Answer:
the second one
Step-by-step explanation:
The scale of this map is 1 inch = 50 miles. The ruler measures the distance between Gary, Indiana, and Traverse City, Michigan, as 3 inches. How many actual miles are between these two cities?
Answers
Answer:
150 miles
Step-by-step explanation:
Given the scale on the map using the conversion factor
1 inch = 50 miles
We are to find the equivalent miles between the cities in miles if the distace is 3inches
3inches = x
Divide both expressions
1/3 = 50/x
Cross multiply
x = 3 * 50
x = 150
Hence the actual distance between these two cities in miles is 150 miles