# a curve is defined by the parametric equations..

• March 29th 2009, 02:04 PM
decoy808
a curve is defined by the parametric equations..
a curve is defined by the parametric equations.....

x=2sint , y=Cost

(a) find the co-ordinates of the point P on the curve for which t= $\pi$/4

(b) (i) find dy/dx in terms of t

(ii) hence find the gradient of a curve at P

any help much appreciated
• March 29th 2009, 02:33 PM
skeeter
Quote:

Originally Posted by decoy808
a curve is defined by the parametric equations.....

x=2sint , y=Cost

(a) find the co-ordinates of the point P on the curve for which t= $\pi$/4

(b) (i) find dy/dx in terms of t

(ii) hence find the gradient of a curve at P

part(a) is basic ... just plug in $\frac{\pi}{4}$ for t and evaluate x and y

part (b) ... $\frac{dy}{dx} = \frac{\frac{dy}{dt}}{\frac{dx}{dt}}$, then evaluate for $t = \frac{\pi}{4}$