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3 years ago

Express the complex number 3(cos270° + i sin270°) in standard a + bi form.

1 answer:

4 0

Answer is choice C
The expression given is equivalent to -3i

============================================

Explanation:

Using a calculator, a reference sheet, or the unit circle, you'll find that:
cos(270) = 0
sin(270) = -1

So this means
z = 3(cos(270)+i*sin(270))
z = 3(0+i*(-1))
z = 3*0+3*i*(-1)
z = 0-3i
z = -3i
which is in a+bi form where a = 0 and b = -3

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Solve the following inequality. Then place the correct answer in the box provided. Answer in terms of a mixed number. 2(P +1) +

Darina [25.2K]

Answer:

$P>-\frac{6}{5}$

Step-by-step explanation:

Isolate the variable by dividing each side by factors that dont't contain the variable.

$2(P+1)+3(P+2)>2$

$2P+2+3P+6>2$

$5P+8>2$

-8 -8

$5P>-6$

Divide both sides by 5.

$P>-\frac{6}{5}$

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3 years ago

Brenda is making a dessert that takes 3.5 hours to prepare. If she wants to be finished by 1:15, at what time should she start??

dusya [7]

3.5 hours is 3 hours and 30 minutes.
1:15 is 1 hour and 15 minutes.

The question is asking at what time does she want to start and end up at 1 hour and 15 minutes? SO you add the time it takes for her to make the dessert with the time at which she ends.

TLTR?? 4:45

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3 years ago

Ian is going to use a computer at an internet cafe. The cafe charges an initial fee to

sergiy2304 [10]

Answer:

C(t) = 6 + .4t

Step-by-step explanation:

Since there is a constant rate of 6 for the first 5 minutes, that would be a value itself. After that, it would always differ by .4 every minute, making this the function.

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4 years ago

all whole numbers are integers. (true or false) all rational numbers are whole numbers. (t or f) there are rational numbers that

8_murik_8 [283]

Answer:

all whole numbers are integers= true

all rational numbers are whole numbers= false

there are rational numbers that are not integers= false

there are whole numbers that are not integers= true

7 0

3 years ago

Read 2 more answers

What is the rectangular equivalence to the parametric equations?

denpristay [2]

Answer:

For x(θ) = 3cosθ + 2

y² = [9x²/(x - 2)²] - x²

For x(θ) = 3cosθ + 2

x² = [4y²/(y - 1)²] - y²

Step-by-step explanation:

Given the following equivalence:

x² + y² = r²

r = √(x² + y²)

x = rcosθ

cosθ = x/r

y = rsinθ

sinθ = y/r

Applying these to the given equations,

x(θ) = 3cosθ + 2

x = 3(x/r) + 2

xr = 3x + 2r

(x - 2)r = 3x

r = 3x/(x - 2)

Square both sides

r² = 9x²/(x - 2)²

(x - 2)²r² = 9x²

(x - 2)²(x² + y²) = 9x²

(x² + y²) = 9x²/(x - 2)²

y² = [9x²/(x - 2)²] - x²

y(θ) = 2sinθ - 1

y = 2y/r - 1

yr = 2y - r

(y - 1)r = 2y

r = 2y/(y - 1)

Square both sides

r² = 4y²/(y - 1)²

x² + y² = 4y²/(y - 1)²

x² = [4y²/(y - 1)²] - y²

8 0

3 years ago