Answer:
D
Step-by-step explanation:
Add real numbers and add imaginary numbers
(-7 + 3i)+(2 - 6i) = -7 + 2 + 3i - 6i
= - 5 - 3i
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
I think it is B or A, but manly A
Step-by-step explanation:

9514 1404 393
Answer:
x = 5, x = 11
Step-by-step explanation:
Set f(x) = 0 and solve for x.
0 = (x -8)² -9
9 = (x -8)² . . . . . add 9
±√9 = x -8 . . . . . take the square root
±3 +8 = x . . . . . . . add 8
That is, ...
x = 8 -3 = 5 . . . . lesser x
x = 8 +3 = 11 . . . greater x