Ask your own question, for FREE!
Mathematics 21 Online
kaylak:

calculus help 10 questions

kaylak:

about to post give me a sec!

kaylak:

@mhchen

kaylak:

@Tranquility

kaylak:

number 6 requires work

kaylak:

@nuts

kaylak:

@Tranquility

kaylak:

@Vocaloid

Vocaloid:

|dw:1542062919231:dw| for 1 just apply the product rule to the derivative and fill in the derivative for csc^-1

Vocaloid:

for 2, identify the parts where the derivative would be 0 (where the slope of the original function is 0), where the derivative is positive (where the original function is increasing) and where the derivative is negative (where the original function is decreasing) and piece together the derivative

Vocaloid:

for 3, just take the derivative wrt x two times

kaylak:

is 1 D?

Vocaloid:

for 4 just take the derivative, plug in x = 2 and round

Vocaloid:

yeah that's what i got too

kaylak:

2 is a or d

Vocaloid:

check again remember the derivative must be positive at both extremes

kaylak:

I meant a or e

kaylak:

sorry

kaylak:

3 is false because it is 3/2 not 5/2

Vocaloid:

there are only two choices (b and d) where the derivative is positive at both extremes of the graph between b and d see which one has the derivative end behavior that matches the behavior of the graph notice how the original graph is increasing at either extreme and only decreasing in the middle

kaylak:

c looks like it since you plot points where it is 0

Vocaloid:

second derivative, not the first derivative

Vocaloid:

3*x^(1/2) first derivative = 3 * (-1/2) * x^(-3/2) second derivative = 3 * (1/2) * (-3/2) * x^(-5/2) = 9/(4x^(5/2))

Vocaloid:

|dw:1542064419769:dw|

Vocaloid:

|dw:1542064427305:dw|

kaylak:

okay that makes sense

kaylak:

so 4 take derivative and then plug 2 in right ?

Vocaloid:

yes

kaylak:

f'(2)=-7/8

Vocaloid:

good they want a decimal to two places so -0.88

kaylak:

yep

kaylak:

Vocaloid:

same logic as before just take the derivative and plug in x = 4

Zarkon:

sneaky... \(\frac{d}{dx}\sin(\ln(-8x^2))\)

kaylak:

that's what I thought

kaylak:

is the sin question correct?

Vocaloid:

i think so

Zarkon:

\(-8x^2\leq0\) therefore \(\ln(-8x^2)\) is undefined

Zarkon:

I'm betting they didn't take that into account when making the question though

Zarkon:

if you allow negative values into the log function then you have to introduce branch cuts

kaylak:

okay so for this sake idk if it's true or false but let me work on the easier ones

kaylak:

-2976

kaylak:

@Vocaloid

Vocaloid:

yeah that's it

kaylak:

I am working on some others and you can check them

kaylak:

1 attachment
kaylak:

@Vocaloid

Vocaloid:

good

kaylak:

1 attachment
kaylak:

do I do 2nd derivative here?

1 attachment
kaylak:

@Vocaloid

2 attachments
kaylak:

last few questions

Vocaloid:

yes you would take the implicit second derivative

kaylak:

so take 2nd and then plug in?

Vocaloid:

yes

kaylak:

I messed up someone could you help me

kaylak:

is 1 of the last 2 correct

kaylak:

@Vocaloid

Vocaloid:

yes

kaylak:

okay so the second derivative question I messed up

Vocaloid:

take the first implicit derivative then solve for the dy/dx term by moving all the variables to one side then take the derivative again

kaylak:

this is what I got

1 attachment
kaylak:

but I have no y to plug in

Vocaloid:

where are you getting c from

kaylak:

the whole dx du formula thing c is constant or something

kaylak:

let's just start over

kaylak:

okay I think I have it now

kaylak:

1/3 or.33

kaylak:

@Vocaloid

kaylak:

one more question above and then 'm done I promise

kaylak:

1 attachment
Vocaloid:

|dw:1542073225421:dw|

Vocaloid:

basically the formula they give you allows you to calculate the slope of the line at x = 9 at infinitely small intervals between 9 and h, giving you the slope of the tangent, and thus, the derivative

kaylak:

what about secnt line

Vocaloid:

i don't think it's relevant here

kaylak:

okay yay thank yo uso much!

Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!
Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!