2(x4) = 35 - (7-4x)
+4x
2(x8)= 28
/2 /2
8x = 14
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:
Step-by-step explanation:
Actually it's 11 because 11 is technically the same when added to constant of x =6 = 11
Considering the number of questions incorrect from classmates on a quiz {10, 11, 12, 13, 13, 13, 14, 15, 16, 16, 17, 18, 18, 19,
IrinaK [193]
Answer:
According to the Empirical Rule, 68% of the data should fall between 11.98 and 18.02
Step-by-step explanation:
We are given the following data in the question:
10, 11, 12, 13, 13, 13, 14, 15, 16, 16, 17, 18, 18, 19, 20
Formula:
where
are data points,
is the mean and n is the number of observations.
Sum of squares of differences = 25 + 16 + 9 + 4 + 4+ 4 + 1 + 0+ 1+ 1 + 4 + 9 + 9+ 16 + 25 = 128

Empirical rule:
- According to this rule almost all the data lies within three standard deviation of the mean for a normal distribution.
- About 68% of data lies within one standard deviation of the mean.
- About 95% of data lies within two standard deviations of mean.
- Arround 99.7% of data lies within three standard deviation of mean.
Thus, by empirical rule,

According to the Empirical Rule, 68% of the data should fall between 11.98 and 18.02
The value of k is 8 hope i was helpful