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Illusion [34]
3 years ago
15

25% of what number is 21

Mathematics
2 answers:
Sergio [31]3 years ago
8 0
21 is 25% of 84.......
makkiz [27]3 years ago
3 0
84 because 21 times 4 equals 84
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Write the square roots of 49 i in ascending order of the angle.
Troyanec [42]

Answer:

The square roots of 49·i in ascending order are;

1) -7·(cos(45°) + i·sin(45°))

2) 7·(cos(45°) + i·sin(45°))

Step-by-step explanation:

The square root of complex numbers 49·i is found as follows;

x + y·i = r·(cosθ + i·sinθ)

Where;

r = √(x² + y²)

θ = arctan(y/x)

Therefore;

49·i = 0 + 49·i

Therefore, we have;

r = √(0² + 49²) = 49

θ = arctan(49/0) → 90°

Therefore, we have;

49·i = 49·(cos(90°) + i·sin(90°)

By De Moivre's formula, we have;

r \cdot (cos(\theta) + i \cdot sin(\theta) )^{\dfrac{1}{2}}  =  \pm \sqrt{r} \cdot \left (cos\left (\dfrac{\theta}{2} \right ) + i \cdot sin\left (\dfrac{\theta}{2} \right ) \right )

Therefore;

√(49·i) = √(49·(cos(90°) + i·sin(90°)) = ± √49·(cos(90°/2) + i·sin(90°/2))

∴ √(49·i) = ± √49·(cos(90°/2) + i·sin(90°/2)) = ± 7·(cos(45°) + i·sin(45°))

√(49·i) = ± 7·(cos(45°) + i·sin(45°))

The square roots of 49·i in ascending order are;

√(49·i) = - 7·(cos(45°) + i·sin(45°))  and  7·(cos(45°) + i·sin(45°))

8 0
3 years ago
Ab" that goes through points (0,17)
KonstantinChe [14]
Yes firebox beans Amanda’s
3 0
2 years ago
Mina uses 128 pounds of dog food to feed her 16 dogs. find the unit rate per dog
MAXImum [283]

The unit rate is 8 pounds per dog.

128 / 16 = 8

7 0
4 years ago
Read 2 more answers
Suppose you budgeted $2800 for fuel expenses for the year. How many miles could you drive if gas were $2.70 per gallon and your
Julli [10]

Answer:

29037.036 miles

Step-by-step explanation

There are two possible ways to solve this problem.

The first option starts with the $2800 dollars for the years. You first want to divide this by $2.70, because it will give you the amount of gallons of gas you can buy with that money.

2800/2.70 = 1037.037

This means you can buy 1037.037 gallons of gas in the year. Now you need to convert this to miles by multiplying by the amount of miles per gallon.

1037.037 x 28 = 29037.036 gallons

The second way to look at this is dimensional analysis. If you have learned this, then continue on reading this, but if you haven't I might only confuse you. I only suggest this because it can make it a little easier.

For the dimensional analysis, you need to start with what you are given and move to what you need to know, so you will start with the $2800 dollars and move to gallons. $2.70 per gallon and 28 miles per gallon are your conversion factors.

Set it up like this:

2800 dollars  * \frac{1 gallon}{2.70 dollars} * \frac{28 miles}{1 gallon}  = 29037.036 miles

This allows the equation to be more organized, and you can check your work by canceling the units.

Hope this helps.

3 0
2 years ago
You have two exponential functions. One function has the formula g(x) = 5 x . The other function has the formula h(x) = 5-x . Wh
Marrrta [24]
Hmm it would be k(x)=2(5x) or it could be k(x)=10x

Hope this helps!
5 0
3 years ago
Read 2 more answers
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