All categories

2 years ago

ΔABC has three sides with these lengths: AB = 9, BC = 40, and CA = 41. What is the value of cos C?

Mathematics

1 answer:

Effectus [21]2 years ago

6 0

From the Law of Cosines
Cos (C) = (a^2 + b^2 -c^2) / 2 * a * b
Cos (C) =(40^2 + 41^2 -9^2) / 2 * 40 * 41
Cos (C) = 1,600 + 1,681 - 81 / 3,280
Cos (C) = 3,200 / 3,280
Cos (C) = 0.9756097561 
Incidentally, Angle C = 12.68 Degrees

You might be interested in

A big cruise ship dropped anchor off the Caribbean island of Antigua. The heavy anchor dropped into the water at a rate of 2.5 m

4vir4ik [10]

Answer:

1) The anchor was released from 72.5 meters above the water's surface.

2)The anchor took 29 seconds to reach the water's surface

Step-by-step explanation:

The rate of drop of anchor = 2.5 meters per second

So, total depth covered by anchor after 45 seconds

= 2.5 meters x 45 seconds

= 112.5 meters

But after 45 minutes, the anchor was 40 meters deep.

So, extra distance traveled by anchor = Total distance covered by anchor - depth of water

= 112.5 meters - 40 meters = 72.5 meters

Hence, the anchor was released from 72.5 meters above the water's surface.

Now, speed of anchor = 2.5 m/sec

So, total time taken to cover extra 72. 5 meters = 72. 5 meters / 2.5 m/sec

= 29 seconds

Hence, the anchor took 29 seconds to reach the water's surface.

8 0

2 years ago

30 POINTS! Explain how you found the equation that represents Aunt Andrea’s decorating plans from the table.

ch4aika [34]

Answer: The number of balloons varies directly with the number of tables. The two variables are directly proportional. The relationship of balloons to tables is the ratio 5:1, where 5 is the constant of variation. Use the equation y = kx, where k is the constant of variation resulting in the equation y = 5x.

Hope i helped

5 0

2 years ago

Read 2 more answers

Peter paid $79.80 for renting a tricycle for 6 hours. What was the rate per hour for renting the tricycle? (Input only numeric v

defon

Answer:

13.30

Step-by-step explanation:

$79.80 / 6 hours = $13.30

3 0

2 years ago

Read 2 more answers

Suppose a marketing company computed a 94% confidence interval for the true proportion of customers who click on ads on their sm

Ksivusya [100]

Answer:

d. There is a 98% chance that the true proportion of customers who click on ads on their smartphones is between 0.56 and 0.62.

Step-by-step explanation:

Confidence interval:

x% confidence

Of a sample

Between a and b.

Interpretation: We are x% sure(or there is a x% probability/chance) that the population mean is between a and b.

In this question:

I suppose(due to the options) there was a small typing mistake, and we have a 98% confidence interval between 0.56 and 0.62.

Interpreation: We are 98% sure, or there is a 98% chance, that the true population proportion of customers who click on ads on their smartphones is between 0.56 and 0.62. Option d.

3 0

2 years ago

Ed buys a vase for £24 and adds 25% onto the price before putting it into his shop window.

lianna [129]

After the 25% discount the vase would cost $18.00

7 0

2 years ago