Cos(2x) = cos^2(x) - sin^2(x) - cos(x)
but sin^2(x) = 1 - cos^2(x)
cos(2x) - cos(x) = cos^2(x) - (1 - cos^2(x) ) - cos(x)
cos(2x) - cos(x) = cos^2(x) - 1 + cos^2(x) - cos(x)
cos(2x) - cos(x) = 2cos^2(x) - 1 - cos(x)
cos(2x) - cos(x) = (2cos(x) + 1)(cos(x) - 1)
I think this is what you have asked for.
Um... it'll take each pipe 80 mins, bcz if together they take that long, then to find the pipes time separately, you just multiply it by two to show it doing the work the other pipe did as well. Is that what you wanted??
The present age of Jane is 45 years old and present age of her sister is 9 years old
<em><u>Solution:</u></em>
Let the present age of Jane be "x"
Let the present age of her sister be "y"
<em><u>Jane is 5 times older than her sister</u></em>
present age of Jane = 5(present age of her sister)
x = 5y ---------- eqn 1
<em><u>In 3 years, Jane’s sister will be 1/4 her age</u></em>
Age of sister after 3 years = 3 + y
Age of jane after 3 years = 3 + x
Age of sister after 3 years = 1/4(age of jane after 3 years)
Substitute eqn 1 in above equation
Substitute y = 9 in eqn 1
x = 5(9)
x = 45
Thus present age of Jane is 45 years old and present age of her sister is 9 years old
0.12 x 70 = 8.4
12% of 70 is 8.4
Answer:
Z-score for 34-week baby = 0.643
Z-score for 41-week baby = 1.154
Baby weight of 41-week is more than the baby weight of 34-week in the gestation period.
Step-by-step explanation:
Given - Suppose babies born after a gestation period of 32 to 35 weeks have a mean weight of 2500 grams and a standard deviation of 700 grams while babies born after a gestation period of 40 weeks have a mean weight of 3100 grams and a standard deviation of 390 grams. If a 34-week gestation period baby weighs 2950 grams and a 41-week gestation period baby weighs 3550 grams
To find - Find the corresponding z-scores. Which baby weighs more relative to the gestation period.
Proof -
Given that,
In between period of 32 to 35 weeks
Mean = 2500
Standard deviation = 700
In between after a period of 40 weeks
Mean = 3100
Standard deviation = 390
Now,
For a 34-week baby,
X = 2950
For a 41-week baby,
X = 3550
Now,
Z-score = (X - mean) / Standard deviation
Now,
For a 34-week baby,
Z - score = (2950 - 2500) / 700 = 0.643
For a 41-week baby,
Z-score = (3550 - 3100) / 390 = 1.154
∴ we get
Z-score for 34-week baby = 0.643
Z-score for 41-week baby = 1.154
As 1.154 > 0.643
So,
Baby weight of 41-week is more than baby weight of 34-week in the gestation period.
