Answer:
First term = -41.
Common difference = -15.
Step-by-step explanation:
nth term: an = a1 + (n - 1)d where a = first term and d = the common difference.
-671 = a1 + (43 - 1)d
-806 = a1 +(52 - 1)d
-671 = a1 + 42d
-806 = a1 + 51d
Subtracting ( to eliminate a1):
-671 - (-806) = 42d - 51d
-9d = 135
d = -15
Substitute for d in the first equation:
-671 = a1 + 42*-15
-671 = a1 - 630
a1 = -671 + 630 = -41.
Cot x = cos x csc x
1/tan x = cosx (1/sin x)
1/(sin x / cos x) = cos x / sin x
cos x / sin x = cos x / sin x
The domain of validity is all real number values of x except for sin x = 0.
<h3>
Answer: No, this isn't a function.</h3>
Why not? Focus on the two points (0,2) and (0,4)
We have the x value x = 0 show up twice. Any time x repeats itself like this, it leads to "not a function" as the result.
In other words, the input x = 0 leads to multiple outputs y = 2 and y = 4 at the same time. A function is only possible if every x input leads to exactly one y output.
If you are a visual learner, then plot all of the points on the same xy grid. Then notice how (0,2) and (0,4) fail the vertical line test to show we don't have a function.
Side note: The y values can repeat themselves in a function.
