Question

Find dx/dy for the following function:

y=sinx+5e^.4x

dx/dy =

Answer 1

is it dx/dy?

Answer 2

what does dx/dy equals

Answer 3

I just want to make sure the question, because dx/ dy !=dy/dx

Answer 4

if it is dx/ dy. it's not easy to solve. you must solve for x first , then take derivative respect to y.

Answer 5

it will behave implicitly

Answer 6

i think she means dy/dx

Answer 7

i thought i had to find the derivative and then solve for y

Answer 8

@mathsmind you help her, ok?

Answer 9

no u help her

Answer 10

can u double check the question plz

Answer 11

it must be dy/dx at ur level

Answer 12

\[Find \frac{ dx }{ dy } for the following function. Y = sinx + 5e ^{0.4x}\]

Answer 13

ok

Answer 14

u allowed everyone to escape from this question hehehehe

Answer 15

lol i know, i wish i could escape it too

Answer 16

dx/dy = 1/(dy/dx)

Answer 17

@jim_thompson5910 rescue me please

Answer 18

ok i will solve it all it is implicit differentiation but in terms of x

Answer 19

so when u diff sin(x) it will be cos(x)dx/dy

Answer 20

and y will become 1 when u differentiate it

Answer 21

ok

Answer 22

Just find dy/dx and take the reciprocal.

Answer 23

nope don't do that

Answer 24

they are not the same

Answer 25

Look, dx/dy = 1/(dy/dx)

Answer 26

no it does not work like that

Answer 27

I hope you're kidding. I'm not manipulating fractions

Answer 28

look multiply both sides

Answer 29

u r missing the chain rule this is calculus not algebra

Answer 30

http://math.stackexchange.com/questions/292590/is-dx-dy-1-dy-dx-in-calculus

Answer 31

the case where u use a reciprocal is by using the chain rule and cancelling each term out

Answer 32

Can't you implicit differentiate in this situation?

Answer 33

implicitly*

Answer 34

yes that is different from ur fomula

Answer 35

im even more confused...

Answer 36

he wants u to use L rule

Answer 37

which is similar to what i said about the chain rule

Answer 38

Lebenz derived a formula from the chain rule

Answer 39

\[\large y=\sin x+5e^{0.4x}\]
\[\large 1=(\cos x +2e^{0.4x})\frac{dx}{dy}\]

Answer 40

nope i told u don't do that, unless if u want to apply Lebenz rule u need to take the inverse of the function then take the reciprocal ...

Answer 41

because calculus is about functions and expansions

Answer 42

read that carefully If the derivative of y = f(x) is dy/dx, then the derivative of the inverse function which expresses x in terms of y is given by the formula

Answer 43

in other words ur Lebenz works if x= sin(y)+5e^y

Answer 44

so u can take the inverse of the function then apply the rule ok

Answer 45

i told u they are not the same but thanks anyway for bribing the topic up

Answer 46

so take the inverse of the function then use the rule

Answer 47

or solve it implicitly as i started

Answer 48

if the case was simple like this then implicit differentiation would have never exist

Answer 49

\[y = \sin(x) + e^{0.4x} \longrightarrow 1=\frac{dx}{dy}\cos(x)+2\frac{dx}{dy}e^{0.4x}\]

Answer 50

the method u use is solving this in an implicit way

Answer 51

take dx/dy as a common factor

Answer 52

well @Xavier ur method also works congratulation!

Answer 53

so both methods work fine, actually u made me come with a new theory in math, or a different proof for Leben'z formula. although maths is not my major, but i will write a new paper on this and publish it

Answer 54

works*

Answer 55

not just that i will change my proof for Kepler's laws of motion ...