Answer: In observational study observer has no control on the variables but in an experiment experimenter has control over the independent variable to record the change on the dependent variable.
Step-by-step explanation:
In statistics , an observational study is a study in which a researcher just observe effects on subjects in a certain manner without interfering them.
On the other hand an experiment is a process which is done by experimenter to demonstrate a known fact or create a discovery by applying some methods to the variables .
The basic difference between an observational study and an experiment is<em> in observational study observer has no control on the variables but in an experiment experimenter has control over the independent variable to record the change on the dependent variable.</em>
Answer:
BEC is 90 degrees
Step-by-step explanation:
solution:
Z1 = 5(cos25˚+isin25˚)
Z2 = 2(cos80˚+isin80˚)
Z1.Z2 = 5(cos25˚+isin25˚). 2(cos80˚+isin80˚)
Z1.Z2 = 10{(cos25˚cos80˚ + isin25˚cos80˚+i^2sin25˚sin80˚) }
Z1.Z2 =10{(cos25˚cos80˚- sin25˚sin80˚+ i(cos25˚sin80˚+sin25˚cos80˚))}
(i^2 = -1)
Cos(A+B) = cosAcosB – sinAsinB
Sin(A+B) = sinAcosB + cosAsinB
Z1.Z2 = 10(cos(25˚+80˚) +isin(25˚+80˚)
Z1.Z2 = 10(cos105˚+ isin105˚)
Answer:
19 days
Step-by-step explanation:
Given
--- initial
-- rate
Required
Days when the fish gets to 30
The function is exponential and as such it follows;
Where x represents the number of days and y the number of fishes
Because the fishes decreases;
So, we have:
Express as decimal
In
So, we have:
Divide both sides by 150
Take log of both sides
Apply law of logarithm
Make x the subject
<em>Hence, it takes approximately 19 days</em>
