Ask question

Ask question

All categories

3 years ago

12

jordan talks to his friends every 15 minutes during class.If the school day last for 6 1/4 hours, how many times will jordan tal

k to his friends

1 answer:

kaheart [24]3 years ago

8 0

Answer: 25 times

Reason: He talks to them 4 times per hour. (6.25)(4) = 25

You might be interested in

Use Simpson's Rule with n = 10 to approximate the area of the surface obtained by rotating the curve about the x-axis. Compare y

DiKsa [7]

The area of the surface is given exactly by the integral,

$\displaystyle\pi\int_0^5\sqrt{1+(y'(x))^2}\,\mathrm dx$

We have

$y(x)=\dfrac15x^5\implies y'(x)=x^4$

so the area is

$\displaystyle\pi\int_0^5\sqrt{1+x^8}\,\mathrm dx$

We split up the domain of integration into 10 subintervals,

[0, 1/2], [1/2, 1], [1, 3/2], ..., [4, 9/2], [9/2, 5]

where the left and right endpoints for the $i$ -th subinterval are, respectively,

$\ell_i=\dfrac{5-0}{10}(i-1)=\dfrac{i-1}2$

$r_i=\dfrac{5-0}{10}i=\dfrac i2$

with midpoint

$m_i=\dfrac{\ell_i+r_i}2=\dfrac{2i-1}4$

with $1\le i\le10$ .

Over each subinterval, we interpolate $f(x)=\sqrt{1+x^8}$ with the quadratic polynomial,

$p_i(x)=f(\ell_i)\dfrac{(x-m_i)(x-r_i)}{(\ell_i-m_i)(\ell_i-r_i)}+f(m_i)\dfrac{(x-\ell_i)(x-r_i)}{(m_i-\ell_i)(m_i-r_i)}+f(r_i)\dfrac{(x-\ell_i)(x-m_i)}{(r_i-\ell_i)(r_i-m_i)}$

Then

$\displaystyle\int_0^5f(x)\,\mathrm dx\approx\sum_{i=1}^{10}\int_{\ell_i}^{r_i}p_i(x)\,\mathrm dx$

It turns out that the latter integral reduces significantly to

$\displaystyle\int_0^5f(x)\,\mathrm dx\approx\frac56\left(f(0)+4f\left(\frac{0+5}2\right)+f(5)\right)=\frac56\left(1+\sqrt{390,626}+\dfrac{\sqrt{390,881}}4\right)$

which is about 651.918, so that the area is approximately $651.918\pi\approx\boxed{2048}$ .

Compare this to actual value of the integral, which is closer to 1967.

4 0

3 years ago

A. 4.5 B. 10 C. 5 D. None of the above ??

prohojiy [21]

Set up a ratio:

12/24 = x/9

Cross multiply:

24x = 108

Divide both sides by 24:

X = 4.5

The answer is 4.5

8 0

4 years ago

Need help please just have to solve

saul85 [17]

CAN BARELY SEE ANYTHING

7 0

3 years ago

the baker's at healthy Baker can make 190 Bagels in 2 hours how many bagels can they make in 15 hours what was the rate per hour

ziro4ka [17]

1425 Bagels can be made in 15 hours at a rate of 95 bagels per hour. In order to solve this equation half the amount of bagels made in 2 hours to find the amount they can make in 1 hour. Next multiply the amount of bagels per hour by 15.

6 0

4 years ago

Bella is wrapping a cube-shaped gift box that measures 8.5 inches along each edge. How many square inches of wrapping paper is n

dybincka [34]

we know that

The surface area of a cube is equal to

$S=6*A$

where

A is the area of one face of the cube

in this problem

$A=8.5^{2}= 72.25\ in ^{2}$

Find the surface area

$S=6*72.25=433.5\ in ^{2}$

therefore

<u>the answer is</u>

$433.5\ in ^{2}$ of wrapping paper is needed to cover the box completely

7 0

3 years ago