Answer: B. Controlled experiment
Step-by-step explanation:
This is a controlled experiment because the variables in the question are manipulated by the researcher. We are told that while one group watches television before going to sleep, the other group does not.
The controllers won't have control over the variables that were used if it was an observational study while for a survey, it has to do with collection of information regarding certain topics or happenings in order to have people's perception on the topic or area of interest.
Answer:
I think they have 2, I could be wrong though
Step-by-step explanation:
The length of a curve
given parametrically by
over some domain
is

In this case,


So we have

and the arc length is

We have

where
is any integer; this tells us
on the interval
and
on
. So the arc length is



Hmmm idk if you want fractions but, 65/24 or 2 17/24 I think
Here's the Answer,
=》sin 45º = cos 45º - <em><u>True</u></em>
=》sin 30º = cos 30° - <em><u>false</u></em>
=》cos 10º = sin 80° - <em><u>true</u></em>
=》sin 15° = cos 75° - <em><u>true</u></em>