Hi can you help me this question.

2sin theta + sin(theta+45) =0

Free 100 points to whoever says “oof the porridges” if it’s not exact, your answer will be reported, first person gets brainliest

What situation is an example of an observational study

Asurvey of 45 teens found that they spent an average of 25.6 hours per week in front of a screen (television, computer, tablet, phone, based on the survey’s sample mean, which value could be the population mean? 2.3 hours 27.4 hours 75.3 hours 41.5 hours