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.
30. Answer if u place the equation into a fraction: example 20/8 yellow over red. Next let’s put the other amount into a fraction, we don’t know yellow so for the fraction we will put x: x/18. For our next step we will then cross multiply 20 by 18 and 8 by x getting 8x=360 from there you divide for x getting 45 yellow.
Answer:
They seem correct!
Step-by-step explanation:
I don’t know pay attention in class and I’m not being mean JK it’s 2,251,926
Answer:
90% confidence interval: (70.41,86.89)
Step-by-step explanation:
We are given the following in the question:
Point estimate = 78.65
Margin of error, E = 8.24
Confidence level = 90%
Significance level = 10%
Formula:

Putting the values, we get,


(70.41,86.89) is the required 90% confidence interval.