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3 years ago

Please help im so confused!!??

Mathematics

1 answer:

victus00 [196]3 years ago

8 0

The formula for the surface area of a cone is SA=(pi)(r^2)+(pi)(r)(l)

L is the slant height of the cone.
Because pi is in the answer choices, there is no need to multiply either by pi so the new formula becomes
SA=r^2+(r)(l)
Now you just plug in what you know
Sa=(8^2) + (8)(15)
Sa=64+120
Sa=184(pi)

*dont forget to put the pi back in since you took it out in the beginning of the equation*

Your answer is A.

Hope this helps :)

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At 5.45p.M .,lixin,khairul and Devil are at the starting point of a 1-km circular path. Lixin Takes 18 minutes to walk one round

sweet [91]

Answer:

$Meeting\ Time = 6:03\ pm$

Step-by-step explanation:

Given

$Start\ Time= 5:45pm$

$Lixin = 18\ min/round$

$Khairul = 360\ seconds/round$

$Devi = 4minutes/2\ rounds$

Required

Determine their next meeting time

First, we need to get their unit rate in minutes per round

$Lixin = 18\ min/round$

$Khairul = 360\ seconds/round$

Convert 360 seconds to minutes

$Khairul = \frac{360}{60} min/round$

$Khairul = 6 min/round$

$Devi = 4minutes/2\ rounds$

Divide by 2/2

$Devi = 2mins/round$

So, we have:

$Lixin = 18\ min/round$

$Khairul = 6 min/round$

$Devi = 2mins/round$

Next, is to determine the LCM of 18, 6 and 2

$18=2 * 3 * 3$

$6 = 2 * 3$

$3 = 3$

Their LCM is:

$LCM = 2 * 3 * 3$

$LCM = 18$

This means that they will meet 18 minutes after their initial time of departure.

So:

$Meeting\ Time = 5:45\ pm + 18\ minutes$

$Meeting\ Time = 6:03\ pm$

3 0

3 years ago

Let f(x)=cos(x)x^-2<br> F’(x)=

kondaur [170]

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