Cotxcos2x = 2cotx
cos2x = 2cotx/cotx
cos2x = 2
cos2x = 2cos²x - 1
2cos²x - 1 = 2
2cos²x = 2+1
2cos²x = 3
cos²x = 3/2
√cos²x = plus minus √(3/2)
cosx = plus minus √(3/2)
What we have here is a problem of proportions. We're assuming that the probabilities - the ratio of rainy days to total days - are equal; 3 is to 20 as <em>something</em> (let's call it <em>r </em>for "rainy days") is to 365. Mathematically, that gives us this equality:
To solve for <em>r</em>, we can simply multiply either side of the equation by 365:
365 and 20 have the factor 5 in common, so we can use that to reduce the fraction to:
So, the number of rainy days, if that pattern continued, would be around 54 3/4 days, or
55, rounded up to the nearest day.
I am pretty sure R is -19 meters and N is -7 and A is 476 AD
Answer:
16
Step-by-step explanation:
Subtracting the given expressions, that is
3b² - 8 - (b(b² + b - 7) ) ← simplify parenthesis
= 3b² - 8 - (b³ + b² - 7b) ← distribute parenthesis by - 1
= 3b² - 8 - b³ - b² + 7b ← collect like terms
= - b³ + 2b² + 7b - 8 ← substitute b = - 3
= - (- 3)³ + 2(- 3)² + 7(- 3) - 8
= - (- 27) + 2(9) - 21 - 8
= 27 + 18 - 21 - 8
= 16