This is for today someone can help me pls!!!

Exercise 2.4.2: Proving statements about rational numbers with direct proofs. About Prove each of the following statements using

IgorLugansk [536]

Answer:

See Explanation

Step-by-step explanation:

(a) Proof: Product of two rational numbers

Using direct proofs.

Let the two rational numbers be A and B.

Such that:

$A = \frac{1}{2}$

$B = \frac{2}{3}$

The product:

$A * B = \frac{1}{2} * \frac{2}{3}$

$A * B = \frac{1}{1} * \frac{1}{3}$

$A * B = 1 * \frac{1}{3}$

$A * B = \frac{1}{3}$

Proved, because 1/3 is rational

(b) Proof: Quotient of a rational number and a non-zero rational number

Using direct proofs.

Let the two rational numbers be A and B.

Such that:

$A = \frac{1}{2}$

$B = \frac{2}{3}$

The quotient:

$A / B = \frac{1}{2} / \frac{2}{3}$

Express as product

$A / B = \frac{1}{2} / \frac{3}{2}$

$A / B = \frac{1*3}{2*2}$

$A / B = \frac{3}{4}$

Proved, because 3/4 is rational

(c) x + y is rational (missing from the question)

Using direct proofs.

Let x and y be

Such that:

$x = \frac{1}{2}$

$y = \frac{2}{3}$

The sum:

$x + y = \frac{1}{2} + \frac{2}{3}$

Take LCM

$x + y = \frac{3+4}{6}$

$x + y = \frac{7}{6}$

Proved, because 7/6 is rational

<em>The above proof works for all values of A, B, x and y; as long as they are rational values</em>

8 0

3 years ago

PLEASE HELP

Savatey [412]

Correct Answer: Option A

The next step in simplification will be to convert the squared term so that it no longer contains a square.

So, we are to simplify the term $cos^{2}(2x)$

Using the half-angle identity we can write:

$cos^{2}(2x)= \frac{1+cos(4x)}{2}$

Using this value, the equation becomes:

$sin^{4}x=1-2cos(2x)+ \frac{ \frac{1+cos(4x)}{2} }{4}$

Therefore, option A is the correct answer.

4 0

3 years ago

Five years ago, you invested $475 in corporate stock. You received dividends of $10 at the end of each quarter for two years. Yo

RUDIKE [14]

The rate of return earned on the investment of $475 five years ago in the corporate stock is 312.63%.

<h3>What is the rate of return?</h3>

The rate of return is the net gain or loss of an investment expressed as a percentage of the investment's initial cost.

It is given by the formula, R= {Vf - Vi}/{Vi} x 100.

Where:

R = Rate of return

Vf = final value, including dividends and interest

Vi = initial value

<h3>Data and Calculations:</h3>

Investment cost = $475

Dividends received:

1st two years = $80 ($10 x 8)

Three years = $180 ($15 x 12)

Total dividends received = $260 ($80 + $180)

Total revenue from sale = $1,700

Total proceeds = $1,960 ($1,700 + $260)

Total return = $1,485 ($1,960 - $475)

Rate of return = 312.63% ($1,485/$475 x 100)

Thus, the rate of return is 312.63%.

Learn more about calculating the rate of return at brainly.com/question/14220025

#SPJ1

8 0

1 year ago

A car traveled 360 km in 6 h. A train traveled 400 km in 8 h. A boat traveled 375 km in 5 h. Which has the fastest average speed

Nataliya [291]

First, it is important to know that speed is equal to distance divided by time. I took a picture of my work. Let me know if you still have questions or cannot read something I've written. Thank you!

The most Kilometers traveled per one hour was traveled by THE BOAT at 75 Km/h. Therefore, the boat had the fastestaverage speed.

8 0

3 years ago

Joe has $70 in a savings account. The interest rate is 10% per year and is not compounded,

sladkih [1.3K]

Answer:

$28

Step-by-step explanation:

First, converting R percent to r a decimal

r = R/100 = 10%/100 = 0.1 per year,

then, solving our equation

I = 70 × 0.1 × 4 = 28

I = $ 28.00

The simple interest accumulated

on a principal of $ 70.00

at a rate of 10% per year

for 4 years is $ 28.00.

8 0

3 years ago