Answer: 
Step-by-step explanation:
The formula for finding the nth term of an arithmetic sequence is given as:

first term = -15
common difference = -6 - (-15) = 9
number of terms
substituting into the formula , we have :


From trigonometry we know that:
if 
then,
(where
is an integer)
This can be rewritten in degrees as:
.............(Equation 1)
Now, in our case, 
Therefore, (Equation 1) can be written as:
..........(Equation 2)
Now, to find the correct options all that we have to do is replace n by relevant integers and find the values of
that match.
For n=2, (Equation 2) gives us:
.
Thus, 
Now, we know that: 
Let n=-1, then:

Thus, 
Likewise, 
Only the last option
will never match
because no integral value of
will ever give 
Thus the last option is the correct option.
<h3>Answer:</h3>
A) ∠A = ∠A' = 38° and ∠B = ∠B' = 42°
<h3>Explanation:</h3>
The sum of angles in ∆ABC is 180°, so ...
... (2x -2) + (2x +2) + (5x) = 180
... 9x = 180
... x = 20
and the angles of ∆ABC are ∠A = 38°, ∠B = 42°, ∠C = 100°.
___
The sum of angles of ∆A'B'C' is 180°, so ...
... (58 -x) +(3x -18) +(120 -x) = 180
... x +160 = 180
... x = 20
and ∠A' = 38°, ∠B' = 42°, ∠C' = 100°.
_____
The values of angle measures of ∆ABC match those of ∆A'B'C', so we can conclude ...
... A) ∠A = ∠A' = 38° and ∠B = ∠B' = 42°
Answer:
A,D,E
Step-by-step explanation:
i. 2t+3t=6t
5t=6t
ii. 2a+2b=4ab
iii. x+3=4x
Answer:
Sin(460 radians)= .97054
sin(460 degrees)= 0.98480775301
Step-by-step explanation:
I'm not sure where you are from, but usually you are allowed to use a calculator. (At least I was when I took Algebra 2/Trig in 6th grade.)
You never specified radians or degrees so I will answer both.
sin(460 radians)= .97054
sin(460 degrees)= 0.98480775301
If you are not allowed to use a calc, then I suggest looking at unit circle videos on Khan Academy.