Sin and cos sin y= in fraction form if you can explain it that would be very

Describe in detail how you would construct a 95% confidence interval for a set of 30 data points whose mean is 20 and population standard deviation is 3. be sure to show that you know the formula and how to plug into it. also, clearly state the margin of error.

The temperature of chicken soup is 192.7°f. as it cools, the temperature of the soup decreases 2.3°f per minute. what is the temperature in degrees fahrenheit of the soup after 25 minutes? a. 27.3°f b. 57.5°f c. 135.2°f d. 250.2°f

[10 points, algebra 2-simplifying complex fractions]according to my answer key the restrictions are -1 and 4. but why not positive 1?