Answer:
When you see a formula like this, try to operate, so you will see some identities sooner or later. In this case, we have a substraction identity:
\frac{cos ( \alpha - \beta )}{cos \alpha cos \beta } = \frac{cos \alpha cos \beta + sin \alpha sin \beta }{cos \alpha cos \beta } = 1 + tan α · tan β
Step-by-step explanation:
Answer:
I think (D)
Step-by-step explanation:
Answer:
C. 17,820
Step-by-step explanation:
30,500-12,680= 17,820
The distribution of the number of occurrences of the letter t on the pages of a book is found to be a normal distribution with a mean of 44 and a standard deviation of 18. If there are 500 pages in the book, which sentence most closely summarizes the data?
A. The letter t occurs less than 26 times on approximately 170 of these pages.
B. The letter t occurs less than 26 times on approximately 15 of these pages.
C. The letter t occurs more than 26 times on approximately 420 of these pages.
D. The letter t occurs more than 26 times on approximately 80 of these pages.
.Answer:
<span>mean = 44 </span>
<span>sd = 18 </span>
<span>that means that "26" is 1 s.d. down, or at the 16th %ile </span>
<span>so, there is a .16 chance that "t" will occur less than 26 times on any single page. </span>
<span>consequently, there is a .84 chance that it will occur more than 26 times on any single page. </span>
<span>Using that information, and knowing that 16% of 500 is 80, and 84% of 500 is 420, can you see where "C" is correct? </span>
The sine function is an odd function, so the sine of -30° is the opposite of the sine of 30°.
sin(30°) = 1/2
sin(-30°) = -1/2
The sine of 30° is greater than the sine of -30°.
