From the double-angle identity,

we can rewritte our given equation as:

By factoring 2cosx on the left hand side, we have

This equation has 2 solutions when

From equation (A), we obtain

and from equation (B), we have

On the other hand, we can find one more solution from the original equation by substituting x=0, that is,

then, x=0 is another solution. In summary, we have obtained the following solutions:

However, the intersection of the last set is empty. So the unique solution is x=0 as we can corroborate on the following picture:
Therefore, the solution set is: {0}
Answer:
C. 7.9 + x
Step-by-step explanation:
Given - A. 7.9x B. 7.9 · (-10) C. 7.9 + x D. - 79
To find - Which expression doesn't belong? Why does it not belong?
Proof -
As given
A. 7.9x
B. 7.9·(-10)
C. 7.9 + x
D. -79
As we can see that Option A, B, D are the multiple of 7.9 but Option C is not the multiple of 7.9
So, Option C does not belong here.
∴ we get
The correct answer is - C. 7.9 + x
Answer: b. Z+5
Step-by-step explanation:
B. Z+5
Let’s say z was 9
The only equation that would work to find 5 more that 9 is 9+5
44.44% is the answer because 4/9 = .4444444 so you would multiply by 100 to get the percent which is 44.44%
Answer:
600
Step-by-step
Think of 0.2 as just 2, if you were to divide 120 by 2 it is simple to solve, the answer is 60, now go back to 120 ÷ 0.2. The best way to think about this is to take the 0 from 0.2 and add it to your answer of 60 sense 0.2 is in the tenths place.