Question

Find dy/dx

Answer 1

\[x=3\cos \theta -\cos^{3} \theta ,y=3\sin \theta-\sin 3 \theta \]

Answer 2

first do dx/dtheta
then dy/dtheta
then divide dx/dtheta by dy/dtheta

Answer 3

Use parametric method

Answer 4

Im not known to the parametric method yet!

Answer 5

I want to learn about that

Answer 6

k i am uploading a small theory about it
give me a minute

Answer 7

yes,thanks!

Answer 8

How will i find the Derivative of sin3theta?

Answer 9

Do you know chain rule of differentiation

Answer 10

yes

Answer 11

chain rule will be used here

Answer 12

will it be like this?
cos3theta + 3costheta

Answer 13

i dont know..

Answer 14

No No nO no no

Answer 15

i am uploading another pic

Answer 16

\[\cos 3 \theta \times \frac {d}{d \theta} \times 3 \theta?\]

Answer 17

Let u=3θ
\[\frac{dy}{d\theta} = \frac{dy}{du}\times\frac{du}{d\theta} = (\frac{d}{du}sinu) \times (\frac{d}{d\theta}3\theta)\]

Answer 18

^^

Answer 19

\[\cos 3 \theta \times \frac {d}{d \theta}(3 \theta)\]

Answer 20

does that mean theta is a function? O_O

Answer 21

i thought it was a variable

Answer 22

Variable :S

Answer 23

lol

Answer 24

Refer to the my previous post..

Answer 25

Not the variable one :S

Answer 26

is it a function or not >.>

Answer 27

yeah yeah

Answer 28

:D

Answer 29

Mr. DLS i think you should review chain rule and parametric equation from the book

Answer 30

yes..

Answer 31

and

Answer 32

\[3\sin \theta = 3\cos \theta+ \sin theta \]

Answer 33

Why?

Answer 34

asking is it correct

Answer 35

UV rule?

Answer 36

no
3sin\[differentiation of 3sintheta=3\cos\]

Answer 37

y not UV?

Answer 38

3 is a constant and (sin) is the the only function so
there we won't be applying UV rule

Answer 39

UV rile is applied when twi functions are in product
F=U.V
U is a function ,
and
V is another function

Answer 40

*rule
*two

Answer 41

okay..tyy

Answer 42

kk
please practice maths daily
differention and integration these two are basic blocks of maths

Answer 43

yes..

Answer 44

Im getting
\[\LARGE \frac{dy}{dx}= \frac{3\cos \theta-3\cos3 \theta}{3 \sin \theta-3 \sin 3 \theta} \]

Answer 45

yes!

Answer 46

\[x=a(cost+\log \tan \frac{t}{2})\]
what do u get on finding the derivative of this?
I got..
\[\frac{dx}{dt}=a(-sint+\frac{1}{2 \sqrt {\tan \frac{t}{2}}} \times \sec^2 \frac{t}{2}\]
just confirming

Answer 47

@hartnn

Answer 48

check this answer once^^

Answer 49

d/dx of log x is 1/x

Answer 50

not , 1/ 2sqrt x

Answer 51

oh yes T_T sorry

Answer 52

rest?

Answer 53

d/dxof tan t/2 = sec^2 t/2 * (1/2)

Answer 54

I SEE :O
thanks!

Answer 55

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