parametric equations

x= 4X2^-t +3
y= 3X2^t -5

a) show dy/dx = -3/4 X 2^2t
b) find the cartesian equation of the curve in the form xy+ax+by=c

Original post by 01sbrals

x= 4X2^-t +3
y= 3X2^t -5

a) show dy/dx = -3/4 X 2^2t
b) find the cartesian equation of the curve in the form xy+ax+by=c

What have you tried?

Reply 2

01sbrals

OP

9

Original post by RDKGames

What have you tried?

I find parametric equations tricky to understand so wanted someone to go through it

Original post by 01sbrals

I find parametric equations tricky to understand so wanted someone to go through it

This isn't really a site for getting guided answers, this is more of a site when you're stuck on a problem and a hint can be given to get you through it.

For dy/dx, you should first determine what dy/dt is. Also then what dx/dt is. Have a go.

Reply 4

01sbrals

OP

9

Original post by RDKGames

This isn't really a site for getting guided answers, this is more of a site when you're stuck on a problem and a hint can be given to get you through it.

For dy/dx, you should first determine what dy/dt is. Also then what dx/dt is. Have a go.

so dx/dt = -8t^-2t
dy/dt = 6t ?

Original post by 01sbrals

so dx/dt = -8t^-2t
dy/dt = 6t ?

Not quite.

Did you mean x,y to be defined as

x=4\cdot 2^{-t} + 3

y = 3 \cdot 2^t - 5

?

Reply 6

Harrybeld

13

Original post by 01sbrals

x= 4X2^-t +3
y= 3X2^t -5

a) show dy/dx = -3/4 X 2^2t
b) find the cartesian equation of the curve in the form xy+ax+by=c

dy/dx=(dy/dt)/(dx/dt)

Reply 7

01sbrals

OP

9

s

Original post by RDKGames

Not quite.

Did you mean x,y to be defined as

x=4\cdot 2^{-t} + 3

y = 3 \cdot 2^t - 5

yes i did

Original post by 01sbrals

s

yes i did

Ok, well you have two options; either go ahead with that I said, but you need to be aware of how to differentiate an expression of the type

a^x

. Given that your attempt above is incorrect, I suggest you look at your textbook for this derivative and use it in your question.

Second option; you can instead aim to eliminate the parameter