ANSWER
The correct choice is A.
EXPLANATION
The given cosine function is:

This function has an amplitude of 2.
Hence it must have range,
-2≤f(t)≤2
It has a period of

Hence the function must complete one cycle on the interval,
[0,½π],
[½π,π],
etc.
The negative sign shows a reflection in the y-axis but since the cosine function is even, the function retraces itself.
The correct choice is A
Answer:
Give us 25 points, but we need question !?
It is associative property
9514 1404 393
Answer:
- central: XWR, VWU
- inscribed: VST
Step-by-step explanation:
Point W is the center of the circle. Any angle with W as its vertex is a central angle:
angles XWR and VWU are central angles
Any angle with its vertex on the circle and rays that intersect the circle is an inscribed angle.
angle VST is an inscribed angle
Answer:
Test is Left tailed test
Parameter tested is standard deviation
Step-by-step explanation:
We are given the hypothesis as;
Null hypothesis; H0: σ = 8.6
Alternative hypothesis; H1: σ < 8.6
Where;σ is a constant generally known in statistics as the standard deviation.
Now, it's the alternative hypothesis that will let us know whether this is left tailed, right tailed or two tailed.
Alternative hypothesis says σ < 8.6.
This means that the values of σ that satisfy this hypothesis are less than 8.6 and thus are on the left hand side of 8.6 on a number line. Thus, the shaded region in a normal distribution curve will be on the left.
Thus, it's a left tailed test