#Help with Calculus Homework

39 messages · Page 1 of 1 (latest)

velvet kettle
#

I would be able to find the P'(2) and Q'(7) if F(x) and G(x) were given in their function form rather than graph, but I don't know how to translate the graph into function form. Could someone walk me through how to translate the graph into it's function

What does the step up for the rate problem look like awell ?

idle slateBOT
static valve
#

use the product rule (and quotient rule)

#

and sub in the values of F' G' F and G at x=2 and x=7

#

using the graphs

velvet kettle
#

Thanks for the fast reply! I'm assuming I can get the value of F and G by just find the y-value when x = 2 or 7, but how do I find F' or G' ?

static valve
#

the points are well chosen

#

look at F'(2) is obv 0

#

its flat

#

G is a straight line ar x=2

#

so you can calculate the slope easily

#

same applies for x=7

velvet kettle
#

Wow it's actually really simple thanks

#

Does that look right ?

static valve
#

F(2) =?

#

Q' is right

velvet kettle
#

Im not sure why I put 2

#

Does that look right ?

static valve
#

its good then

velvet kettle
#

Thanks man !

#

Do you know how I can set up the second problem ?

static valve
#

dont be fooled by physics

#

they just want you to differentiate R with respect to time

#

using quotient rule

#

you can differentiate both sides of the equation

#

then solve for dR/dt

#

and sub in all the values

velvet kettle
#

I have no idea

static valve
#

differentiate first

#

d/dt(1/R) = d/dt(1/R1 + 1/R2)

#

calculate this

velvet kettle
#

Its an activity that my teacher gave us

#

Dont know where he got it

idle slateBOT
ebon smelt
#

\begin{align*}
\frac1R&=\frac1{R_1}+\frac1{R_2}\
R&=\frac1{\frac1{80}+\frac1{100}}=\frac1{1/80+1/100}=\frac{400}9\
-\frac1{R^2}\dv{R}{t}&=-\frac1{R_1^2}\dv{R_1}{t}-\frac1{R_2^2}\dv{R_2}{t}\
\dv{R}{t}&=R^2\qty(\frac1{R_1^2}\dv{R_1}{t}+\frac1{R_2^2}\dv{R_2}{t})\
&=\qty(\frac{400}9)^2\qty(\frac1{80^2}\cdot0.3+\frac1{100^2}\cdot0.2)\
&=\boxed{\frac{655}{162}\frac{\Omega}{\text s}}\end{align*}

glad solsticeBOT
#

mtt07734

ebon smelt
#

.solved