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
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
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:
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
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.
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:
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
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
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
Which statement is true ?
Answers
Answer:
the second one
Step-by-step explanation:
Please help me with this..
Answers
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:
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 :'(
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
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
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
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
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
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.
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
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
(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!
Write the ratio in simplest form.
The ratio of green beads : total number of beads is ???
Answers
Answer:
3:15
Step-by-step explanation:
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:
Jupiter,Saturn or Uranus?
Answers
Answer:
Jupiter :)
Step-by-step explanation:
£1 = $1.5 dollars
Convert £20 into dollars
Answers
Answer:
$30
Step-by-step explanation:
1.5 x 20 = 30
Write 5.164 x 10^-4 in standard form.*
Answers
Answer is 0.0005164x
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:
Graph the following
y−2=2/3(x+4)
Answers
6x^3 -x^2-10x-3 by 2x-3
Answers
Answer:
Quotient : 3x² + 5x + 1
Step-by-step explanation:
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