3 years ago

CosA.cos2A.cos4A=sin8A/8sinA

Mathematics

1 answer:

alexgriva [62]3 years ago

3 0

I assume you're supposed to establish the identity,

cos(A) cos(2A) cos(4A) = 1/8 sin(8A) / sin(A)

Recall the double angle identity for sine:

sin(2x) = 2 sin(x) cos(x)

Then you have

sin(8A) = 2 sin(4A) cos(4A)

sin(8A) = 4 sin(2A) cos(2A) cos(4A)

sin(8A) = 8 sin(A) cos(A) cos(2A) cos(4A)

==> sin(8A)/(8 sin(A)) = cos(A) cos(2A) cos(4A)

as required.

You might be interested in

What is the decimal Expansion of the following fraction?

mars1129 [50]

Answer:

Step-by-step explanation:

1/25 = 0.04 only. this is surely the anwer

4 0

3 years ago

At the end of the year, Close made the current year on mark down to make Room for next year models. One particular model had a s

SCORPION-xisa [38]

Answer: 5%.

Step-by-step explanation:

Given data:

Old price = $28,640

New price = $27,208

Solution:

Percentage of decrease

= old price - new price / old price * 100

= $28,640 - $27,208 /. $28,640 * 100

= $1432/$28,640*100

= 0.05*100

= 5%.

The percentage of decrease for the car is 5%.

5 0

3 years ago

Find the mean median of each data set.

joja [24]

Median 72.5
Mean is 76

8 0

3 years ago

Given the system of equations, what is the value of the system determinant?

weeeeeb [17]

2x + y = 8
x - y = 10
--------------add
3x = 18
x = 6

x - y = 10
6 - y = 10
-y = 10 - 6
-y = 4
y = -4

solution is : (6,-4)

6 0

3 years ago

Read 2 more answers

What is the distance between (1,-5) and (-3,6)

Wewaii [24]

Answer:

$\large\boxed{\sqrt{137}\approx11.7}$

Step-by-step explanation:

The formula of a distance between two points:

$d=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}$

We have two points (1, -5) and (-3, 6). substitute:

$d=\sqrt{(-3-1)^2+(6-(-5))^2}=\sqrt{(-4)^2+11^2}=\sqrt{16+121}=\sqrt{137}$

4 0

3 years ago

CosA.cos2A.cos4A=sin8A/8sinA​

CosA.cos2A.cos4A=sin8A/8sinA