Answer:
the first one is right and other are wrong
Answer:
(3/8) + (1/8)cos 4x - (1/2)cos 2x
Step-by-step explanation:
sin^(4) x = (sin² x ) (sin² x) ------ (1)
Recall double angle identity: cos 2x = 1 - 2 sin² x
or sin² x = (1/2) (1 - cos 2x)
substituting this into (1)
sin^(4) x = (sin² x ) (sin² x) = [ (1/2)(1-cos 2x) ]²
= (1/4) ( 1 - 2 cos 2x + cos²2x) ------(2)
Also recall double angle identiy : cos 2x = 2 cos² x - 1
or cos² x = (1/2) ( 1+ cos 2x)
or cos² 2x = (1/2) ( 1+ cos 4x)
substituting this into (2)
(1/4) ( 1 - 2 cos 2x + cos²2x)
= (1/4) [ 1 - 2 cos 2x + (1/2)(1 + cos 4x) ] (expand and reduce)
= (3/8) + (1/8)cos 4x - (1/2)cos 2x
The answer to the question is 33.3
Answer:
2.06
Step-by-step explanation:
The formula for critical value = Margin of Error / Standard Error
Margin of Error = z × Standard deviation/√n
Mean for the month of March = $305.30
Standard deviation = $46.50
n = number of samples = 26 homes
z score for 95% confidence interval = 1.96
= 1.96 × $46.50/√26
= 17.874024556
Standard error = standard deviation/√n
= $46.50/√26
= 9.1194002839
Critical value = Margin of Error/Standard Error
= 17.874024556/9.1194002839
= 2.06
Whats your question exactly?