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Sati [7]
2 years ago
12

Prove that:cos20°cos40°cos80°=1/8​

Mathematics
2 answers:
Naya [18.7K]2 years ago
7 0

Answer:

see explanation

Step-by-step explanation:

Using the double angle identity for sine

sin2x = 2sinxcosx

Consider left side

cos20°cos40°cos80°

= \frac{1}{2sin20} (2sin20°cos20°)cos40°cos80°

= \frac{1}{4sin20} (2sin40°cos40°)cos80°

= \frac{1}{4sin20} (sin80°cos80° )

= \frac{1}{8sin20} (2sin80°cos80° )

= \frac{1}{8sin20} . sin160°

= \frac{1}{8sin20} . sin(180 - 20)°

= \frac{1}{8sin20} . sin20°

= \frac{1}{8} = right side , thus proven

viva [34]2 years ago
7 0

Step-by-step explanation:

hope its helps you have a great day keep smiling be happy stay safe ☺

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15. Cedric lives at one end of Main Street, and Landon lives at the other end of the street. Main Street is 6.02 Kilometers long
emmainna [20.7K]

Answer:

2,120 m

Step-by-step explanation:

Cedric lives at one end of Main Street, and Landon lives at the other end of the street

Main Street is 6.02 Kilometers long. Cedric walks 3.9 kilometers toward Landon's house.

Step 1

We calculate the kilometers Cedric has to walk to arrive at Landon's house

This is given as:.

6.02km - 3.9 km

= 2.12 km

Step 2

How many more meters must Cedric walk to arrive at Landon's house?

We convert from km to m

1 km = 1000m

2.12km = x

Cross Multiply

x = 2.12 × 1000m

x = 2120 m(meters)

7 0
2 years ago
True or False
lora16 [44]

Answer: True i believe

Step-by-step explanation:

3 0
3 years ago
Read 2 more answers
Suppose the time that it takes a certain large bank to approve a home loan is Normally distributed with mean (in days) μ and sta
kolezko [41]

Answer:

(c) H0 should be rejected

Step-by-step explanation:

Null hypothesis (H0): population mean is equal to 5

Alternate hypothesis (Ha): population mean is greater than 5

Z = (sample mean - population mean) ÷ (sd/√n)

sample mean = 5.3, population mean = 5, sd = 1, n = 500

Z = (5.3 - 5) ÷ (1/√500) = 0.3 ÷ 0.045 = 6.67

Using the normal distribution table, for a one tailed test at 0.01 significance level, the critical value is 2.326

Conclusion:

Since 6.67 is greater than 2.326, reject the null hypothesis (H0)

4 0
3 years ago
What’s the correct answer for this?
Anvisha [2.4K]

Answer:

P = 4/13

Step-by-step explanation:

In a deck of 52 cards, there are 3 aces(spade, heart, diamond), 1 club ace, and 12 remaining club cards

=> The probability of randomly drawing 1 card that is an ace card or a club card:

P = number of elements/total number of elements

P = (3 + 1 + 12)/52

P = 16/52

P = 4/13

=> Option A is correct

8 0
3 years ago
Point A is at (-1, -9) and point M is at (0.5, -2.5).
vladimir2022 [97]

Answer:

Point B is located at point (2, 4)

Step-by-step explanation:

Since point M is at the center, you find the distance from point A and add that to the other side.

| -1 - 0.5 | = | -1.5 | = 1.5

| -9 - -2.5 | = | -6.5 | = 6.5

Now we can add that to point M to find point B

0.5 + 1.5 = 2

-2.5 + 6.5 = 4

Point B should be at (2, 4)

4 0
3 years ago
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