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3 years ago

The formula for the surface area of a cylinder is A=2πr(r+h).Find h if A=80π and r=5.

Mathematics

1 answer:

Olin [163]3 years ago

6 0

Here's the steps (if you know how just do this equation as if it was a literal equation)

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The ratio of boys to girls in Mr. Garcia's class is 3:5. There 10 girls in the class. How many boys are in the class

MrRa [10]

There are 6 boys in the classroom

7 0

4 years ago

It took 48 minutes to drive downtown. An app estimated it would be less than that. If the error was 20%, what was the app’s esti

IgorLugansk [536]

Answer:

The estimated taken to drive downtown using App is 38.4 minutes

Step-by-step explanation:

Given as :

The initial time taken to drive downtown = i = 48 minutes

The percentage error of time = r = 20%

Let The estimated time using app = t min

Let the time = 1 min

<u>Now, according to question</u>

The estimated time using app = The initial time taken to drive downtown × $(1-\dfrac{\textrm rate}{100})^{\textrm time}$

Or, t minutes = i minutes × $(1-\dfrac{\textrm r}{100})^{\textrm 1}$

Or, t = 48 minutes × $(1-\dfrac{\textrm 20}{100})^{\textrm 1}$

Or, t = 48 minutes × $\dfrac{100-20}{100}$

Or, t = 48 minutes × $\dfrac{80}{100}$

∴ t = $\dfrac{48\times 80}{100}$ minutes

I.e t = 38.4 minutes

Or, The estimated time using app = t = 38.4 min

Hence, The estimated taken to drive downtown using App is 38.4 minutes Answer

5 0

3 years ago

Y=x.arctan(x)^1/2. find dy/dx. pls show steps

Whitepunk [10]

$y=x(\arctan x)^{1/2}$

Use the product rule first:

$\dfrac{\mathrm dy}{\mathrm dx}=\dfrac{\mathrm dx}{\mathrm dx}(\arctan x)^{1/2}+x\dfrac{\mathrm d(\arctan x)^{1/2}}{\mathrm dx}$

$\dfrac{\mathrm dy}{\mathrm dx}=(\arctan x)^{1/2}+x\dfrac{\mathrm d(\arctan x)^{1/2}}{\mathrm dx}$

Use the chain rule to compute the derivative of $(\arctan x)^{1/2}$ . Let $z=(\arctan x)^{1/2}$ and take $u=\arctan x$ , so that by the chain rule

$\dfrac{\mathrm dz}{\mathrm dx}=\dfrac{\mathrm dz}{\mathrm du}\dfrac{\mathrm du}{\mathrm dx}$

$\dfrac{\mathrm dz}{\mathrm du}=\dfrac{\mathrm du^{1/2}}{\mathrm du}=\dfrac12u^{-1/2}$

$\dfrac{\mathrm du}{\mathrm dx}=\dfrac{\mathrm d\arctan x}{\mathrm dx}=\dfrac1{1+x^2}$

$\implies\dfrac{\mathrm d(\arctan x)^{1/2}}{\mathrm dx}=\dfrac1{2(\arctan x)^{1/2}(1+x^2)}$

So we have

$\dfrac{\mathrm dy}{\mathrm dx}=(\arctan x)^{1/2}+\dfrac x{2(\arctan x)^{1/2}(1+x^2)}$

You can rewrite this a bit by factoring $(\arctan x)^{-1/2}$ , just to make it look neater:

$\dfrac{\mathrm dy}{\mathrm dx}=\dfrac1{2(\arctan x)^{1/2}}\left(2\arctan x+\dfrac x{1+x^2}\right)$

3 0

3 years ago

PLSSS HELP IF YOU TURLY KNOW THISS AND PLSS EXPLAIN :)

fenix001 [56]

Answer:

x = -7

Step-by-step explanation:

first you collect like terms but since there is an =sign you take +4 over the = to 10 and 6x to 8x it becomes 8x - 6x = -4 - 10 and you solve it becomes 2x = -14 hence answer is x = -7

7 0

3 years ago

Read 2 more answers

This is a question for advanced calculus V=lwh?

dangina [55]

V = l.w.h

Solving for l

l = V/wh

Solving for w

w = V/lh

Solving for h

h = V/lw

3 0

4 years ago

Read 2 more answers