The expression that is not a variation of the Pythagorean identity is the third option.
<h3>
What is the Pythagorean identity?</h3>
The Pythagorean identity can be written as:

For example, if we subtract cos^2(x) on both sides we get the second option:

Which is a variation.
Now, let's divide both sides by cos^2(x).

Notice that the third expression in the options looks like this one, but the one on the right side is positive. The above expression is in did a variation of the Pythagorean identity, then the one written in the options (with the 1 instead of the -1) is incorrect, meaning that it is not a variation of the Pythagorean identity.
Concluding, the correct option is the third one.
If you want to learn more about the Pythagorean identity, you can read:
brainly.com/question/24287773
Answer: 0.0775
Step-by-step explanation:
Given : Mean : 
Standard deviation : 
Sample size : 
Since its normal distribution , then the formula to calculate the z-score is given by :-

For x= 28.2 hours

For x= 30 hours

The P- value = 

Hence, the probabiliy that the average time spent stydying for the sampe was between 28.2 and 30 hours = 0.0775
Answer:
$5.76
Step-by-step explanation:
Total price for 3.75 pounds of pears:

Total price for 2.10 pounds of pears:

Total Price:

The answer is 5/72 you would just divide 5/6 by 12 hope this helped