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3 years ago

If something that is 15.00 is 80%off what is the price

Mathematics

2 answers:

mixas84 [53]3 years ago

7 0

Answer:

you will pay 3 for a item with original price of $15 when discounted 80%. In this example, if you buy an item at $15 with 80% discount, you will pay 15-12= 3

Step-by-step explanation:

so the anwser is 3 :)

liberstina [14]3 years ago

5 0

Answer:

So I think its either 75 or 3

Step-by-step explanation:

for 80% of 15 its 3. 20% is fifteen. 20 times 5 is 100 so I did 15 times 5 to get the answer 75. I hope this helps!

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What is 5.9% of 100%

In-s [12.5K]

5.9% of 100 would be 5.9 all you have to do is divide your percentage by 100, once you have the decimal multiply it by the whole number you have which would be 100

4 0

3 years ago

Please help me thank you

zhuklara [117]

Answer:

Answer choice B

Step-by-step explanation:

6 0

3 years ago

Read 2 more answers

How to find the derivative of cos^2x? i seem to be confused.

slamgirl [31]

If you're using the app, try seeing this answer through your browser: brainly.com/question/2927231

————————

You can actually use either the product rule or the chain rule for this one. Observe:

• Method I:

y = cos² x

y = cos x · cos x

Differentiate it by applying the product rule:

$\mathsf{\dfrac{dy}{dx}=\dfrac{d}{dx}(cos\,x\cdot cos\,x)}\\\\\\
\mathsf{\dfrac{dy}{dx}=\dfrac{d}{dx}(cos\,x)\cdot cos\,x+cos\,x\cdot \dfrac{d}{dx}(cos\,x)}$

The derivative of cos x is – sin x. So you have

$\mathsf{\dfrac{dy}{dx}=(-sin\,x)\cdot cos\,x+cos\,x\cdot (-sin\,x)}\\\\\\
\mathsf{\dfrac{dy}{dx}=-sin\,x\cdot cos\,x-cos\,x\cdot sin\,x}$

$\therefore~~\boxed{\begin{array}{c}\mathsf{\dfrac{dy}{dx}=-2\,sin\,x\cdot cos\,x}\end{array}}\qquad\quad\checkmark$

—————

• Method II:

You can also treat y as a composite function:

$\left\{\!
\begin{array}{l}
\mathsf{y=u^2}\\\\
\mathsf{u=cos\,x}
\end{array}
\right.$

and then, differentiate y by applying the chain rule:

$\mathsf{\dfrac{dy}{dx}=\dfrac{dy}{du}\cdot \dfrac{du}{dx}}\\\\\\
\mathsf{\dfrac{dy}{dx}=\dfrac{d}{du}(u^2)\cdot \dfrac{d}{dx}(cos\,x)}$

For that first derivative with respect to u, just use the power rule, then you have

$\mathsf{\dfrac{dy}{dx}=2u^{2-1}\cdot \dfrac{d}{dx}(cos\,x)}\\\\\\
\mathsf{\dfrac{dy}{dx}=2u\cdot (-sin\,x)\qquad\quad (but~~u=cos\,x)}\\\\\\
\mathsf{\dfrac{dy}{dx}=2\,cos\,x\cdot (-sin\,x)}$

and then you get the same answer:

$\therefore~~\boxed{\begin{array}{c}\mathsf{\dfrac{dy}{dx}=-2\,sin\,x\cdot cos\,x}\end{array}}\qquad\quad\checkmark$

I hope this helps. =)

Tags: <em>derivative chain rule product rule composite function trigonometric trig squared cosine cos differential integral calculus</em>

3 0

4 years ago

Exponential form of 1/8

geniusboy [140]

I believe its 2 ^ -3

because

1/8 = 1/2^3 = 2^-3

4 0

3 years ago

In a group of 60 workers, the average (arithmetic mean) salary is $80 a day per worker. If some of the workers earn $75 a day an

Tomtit [17]

Let's let x = the number of workers making $75 per day
Then that would mean (60 - x) would be the number of workers who make $100 per day.
Now the average salary, which needs to be 80, can be found by adding all the salaries of the 60 workers and dividing by 60. The following equation can model this problem:
[75x + 100(60 - x)]/60 = 80 simplify the left side of the equation
(-25x + 6000)/60 = 80 multiply both sides by 60
-25x + 6000 = 4800 subtract 6000 from both sides
-25x = -1200 divide both sides by -25
x = 48 recall we set 'x' to equal the number of workers making $75 per day
And there you have it! Hope this helps..

8 0

4 years ago

Read 2 more answers