Answer:
Option A is correct.
Solution for the given equation is, 
Step-by-step explanation:
Given that : 
Let 
then our equation become;
.....[1]
A quadratic equation is of the form:
.....[2] where a, b and c are coefficient and the solution is given by;

Comparing equation [1] and [2] we get;
a = 2 b = -1 and c =-1
then;

Simplify:

or


or
and 
Simplify:
y = 1 and
Substitute y = cos x we have;

⇒
and

⇒
The solution set: 
Therefore, the solution for the given equation
is, 
The correct answer is D.
X=7
8=7+1
8=8
Answer:
f I used to know this one
Answer: convenience sampling
Step-by-step explanation:
Convenience sampling is also referred to as opportunity sampling or accidental sampling and it occurs when a sample is selected from the population that is convenient and close to hand for the researcher. It's usually used during pilot testing.
Convenience sampling is such that the primary data source that are first available will be used for the research without any additional requirements being made.