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3 years ago

Verify that: cos(x+y)cos(x-y)=cos^2x-sin^2y

1 answer:

4 0

COS(X+Y)COS(X-Y)
=(COSX*COSY-SINX*SINY)(COSX*COSY+SINX*SINY)
=(COSX*COSY)^2-(SINX*SINY)^2
=COS^2 X(1-SIN^2 Y)-(1-COS^2 X)SIN^2 Y
=COS^2 X -COS^2 X*SIN^2 Y-SIN^2 Y +COS^2 X SIN^2 Y
<span>=COS^2X-SIN^2Y</span>

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WILL GIVE BRAINLIST! :)) AND 20 POINTS

abruzzese [7]

Answer:

1. D

2. D

3. H

4. B

5. B

Step-by-step explanation:

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3 years ago

a textbook company ships its books in boxes that can hold 30 pounds. one particular order calls for a shipment of 800 books. if

Pachacha [2.7K]

83 boxes are required to carry 800 books.

According to the question:

One Box can hold weight = 30 pounds

We know that , 1 pound= 0.45 kg

hence, 30 pounds = 30 x 0.45 = 13.5kg

hence, one box can carry 13.5 kg of weight.

Now,

Weight of 1 book = 1.4 kg

So, Total Weight of 800 books= 1.4 x 800 kg

And , No. of boxes required to carry 800 books = (1.4 x 800)/13.5 = 82.96

or approximately 83 boxes

Hence, 83 boxes are required to carry 800 books.

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brainly.com/question/19423643

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2 years ago

Jason is making pumpkin bread. He needs 8 cups of pumpkin for every 4 cups of sugar.What is the ratio of cups of sugar to cups o

VladimirAG [237]

Answer:

4:8

Step-by-step explanation:

3 0

3 years ago

beni is shopping for a new cell phone plan. company a charges$72.25for a new phone and $85.50 per month.company b charges $151.2

tigry1 [53]

Missing questions and subsequent solutions:
(a) Write an equation for company A for cost, C, number of months, n, that Beni will pay for the phone.

Solution:
For company A:
C = 72.25 + 85.50n

(b) Write an eqyation for company B for cost, C, and number of months, n, that Bei will pay for the phone.

Solution:
For company B:
C = 151.25 + 65.75n

(c) Write an inequality when the cost from company A is better than cost from company B.

Solution:
72.25 + 85.50n ≤ 151.25 + 65.75n
(85.50-65.75)n ≤ (151.25 - 72.25)
19.75 n ≤ 79
n ≤ 4

(d) Value of n for which cost from the two companies will be the same.

Solution:
If cost for companies A and B are the same, then
72.25 + 85.50n = 151.25 + 65.75n
(85.5 - 65.75)n = 151.25 - 72.25
19.75n = 79
n = 79/19.75 = 4 months

After 4 months,
C = 72.25 + 85.5*4 = $414.25

7 0

3 years ago

15% out of 365 days, about how many days can residents predict rain?

Liula [17]

54 days!!!!!!!!!!!!!!!!!!!!!!!!!!!1

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3 years ago

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