Answer:
see explanation
Step-by-step explanation:
Using the Pythagorean identity
cos²A + sin²A = 1 ( divide terms by cos²A )
+ 
= 
, that is
1 + tan²A = sec²A ← as required
This is an example of "a stratified sample".
<u>Answer:</u> Option B
<u>Explanation:</u>
A group-based sampling process that can be divided into subpopulations. For statistical studies, testing of each subpopulation separately may be useful if subpopulations within a total population differ, thus understood as "Stratified sampling".
One might, for instance, divide a adults sample into subgroups in terms of age, like 18 to 29, 30 to 39, 40 to 49, 50–59 etc with decided age difference as needed. A stratified sample may be more accurate than an easy sample of the similar size by random. As it offers more accuracy, a stratified sample sometimes involves a smaller sample, saving money.
What do you mean angle 6?
