Answer:
No, none of the number need to be 48 for the mean to be 48. To get a mean, you add up all the number and divide it by the amount of numbers.
Example:
the mean of 10, 79, 42, 88, 19, and 50 is 48, but the actual number 48 was not part of the set.
10 + 79 + 42 + 88 + 19 + 50 = 288
288 ÷ 6 = 48
Answer: see proof below
<u>Step-by-step explanation:</u>
Use the Double Angle Identity: sin 2Ф = 2sinФ · cosФ
Use the Sum/Difference Identities:
sin(α + β) = sinα · cosβ + cosα · sinβ
cos(α - β) = cosα · cosβ + sinα · sinβ
Use the Unit circle to evaluate: sin45 = cos45 = √2/2
Use the Double Angle Identities: sin2Ф = 2sinФ · cosФ
Use the Pythagorean Identity: cos²Ф + sin²Ф = 1
<u />
<u>Proof LHS → RHS</u>
LHS: 2sin(45 + 2A) · cos(45 - 2A)
Sum/Difference: 2 (sin45·cos2A + cos45·sin2A) (cos45·cos2A + sin45·sin2A)
Unit Circle: 2[(√2/2)cos2A + (√2/2)sin2A][(√2/2)cos2A +(√2/2)·sin2A)]
Expand: 2[(1/2)cos²2A + cos2A·sin2A + (1/2)sin²2A]
Distribute: cos²2A + 2cos2A·sin2A + sin²2A
Pythagorean Identity: 1 + 2cos2A·sin2A
Double Angle: 1 + sin4A
LHS = RHS: 1 + sin4A = 1 + sin4A 
Answer:
150 • r + 62 = 40
Step-by-step explanation:
6 - hundred thousand
1 - ten thousands
2 - thousands
3 - hundred
0 - tens
0 - ones
600,000 + 10,000 + 2,000 + 300
Sum and Difference Formula for Cosine: cos(α±β)= cosαcosβ <span>∓ sin</span>αsinβ
cos(8x+2x)=cosαcosβ-sinαsinβ
cos(10x)=cosαcosβ-sinαsinβ