A three-dimensional vector field is conservative if it is also irrotational, i.e. its curl is

. We have

so this vector field is not conservative.
- - -
Another way of determining the same result: We want to find a scalar function

such that its gradient is equal to the given vector field,

:

For this to happen, we need to satisfy

From the first equation, integrating with respect to

yields

Note that

*must* be a function of

only.
Now differentiate with respect to

and we have

but this contradicts the assumption that

is independent of

. So, the scalar potential function does not exist, and therefore the vector field is not conservative.
Answer
this is hard
explanation
sorry i can’t answer i’m bad at math
Answer:
Option A. 3.5x + 15 ≥ 55
Step-by-step explanation:
Points Rosh received for becoming a member = 15
Points Rosh received for visiting the moving theater = 3.5
Total points needed for a free movie ticket = 55
For each visit he receives 3.5 points, so for x visits he will receive 3.5x points.
Total points = Points received on becoming a member + Points received on x visits
So,
Total Points = 15 + 3.5x
These points must be at least 55 for a free movie ticket. At least means equal to or greater than. So the total points must be equal to or greater than 55 in order to earn a free movie ticket. This can be expressed as:
3.5x + 15 ≥ 55
So, option A gives the correct answer
The probability p of an orangecandy is 0.2. The sample size = 100.
The mean is given by:

The standard deviation is given by:

The answers are: Mean = 20. Standard deviation = 4.
Answer:
It's D.
Step-by-step explanation:
The shorter period loan has the same total interest for the same loan amount, so it has the higher effective interest rate: 80/12 is higher than 89/14.