MedVision ad

Parametrics Help (1 Viewer)

OH1995

Member
Joined
Nov 7, 2011
Messages
150
Gender
Male
HSC
2013
Hello wonderful people,

Would you please be able to help me with this question:

Eliminate the parameter and hence find the cartesian equation of the curve;

x=1+2tanø and y=3secø-4

Thanks!
 

RivalryofTroll

Sleep Deprived Entity
Joined
Feb 10, 2011
Messages
3,805
Gender
Male
HSC
2013
Uni Grad
2019
(x-1)/2 = tanx
(y+4)/3 = secx

Since sec^2x - tan^2x = 1

Yeah, you know what to do now.
 

Aesytic

Member
Joined
Jun 19, 2011
Messages
141
Gender
Male
HSC
2012
y = 3sec(theta) - 4
y+4 = 3sec(theta)
sec^2(theta) = (y+4)^2/9 ----- 1

x=1+2tan(theta)
tan(theta) = (x-1)/2
tan^2(theta) = (x-1)^2/4 ----- 2

1 - 2:
sec^2(theta) - tan^2(theta) = (y+4)^2/9 - (x-1)^2/4
1 = (y+4)^2/9 - (x-1)^2/4
 

OH1995

Member
Joined
Nov 7, 2011
Messages
150
Gender
Male
HSC
2013
Oh wow, thanks. Haha I didn't see the trig identity!
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top