Math Is Fun Forum

Au101

Member

Registered: 2010-12-01

Posts: 353

Differentiation

Hi guys,

I have a question about differentiation, which I'm not quite sure how to set out:

---

The curve C has parametric equations

Find an equation of the tangent to C at A (1,1).

---

Now

And obviously I have a y-coordinate and an x-coordinate.

I'm not so sure about finding the gradient, do I have to let x and y equal 1 and find that t=1?

Last edited by Au101 (2011-02-20 01:40:22)

Bob

Administrator

Registered: 2010-06-20

Posts: 10,583

Re: Differentiation

hi Au101,

Nice to hear from you.  How's the study going?

( dy/dx correct btw )

Yes, put t = 1 throughout to get point (1,1) as required and gradient = 2/3.

Then just use y = mx + c to find c.

Bob

Last edited by Bob (2011-02-20 02:03:22)

---

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

Au101

Member

Registered: 2010-12-01

Posts: 353

Re: Differentiation

Hi Bob, it's good to hear from you too.

Okay, so

So do I then discard t=-1 and sub in t=1?