Parametric equation

Need help with the last part i dont get the mark scheme.
I got dy/dx=0. i get the bit about the normal being undefined but I dont get the x=tan(pi/4)
Therefore x=1 bit. What happens to y?
http://m.imgur.com/z2zjGFt,kZKYEPh

Reply 1

Zacken

22

Original post by Super199

Need help with the last part i dont get the mark scheme.
I got dy/dx=0. i get the bit about the normal being undefined but I dont get the x=tan(pi/4)
Therefore x=1 bit. What happens to y?
http://m.imgur.com/z2zjGFt,kZKYEPh

It's a vertical straight line. x=1.

Reply 2

Super199

OP

20

Original post by Zacken

It's a vertical straight line. x=1.

How did you know that? Why cant it be y=1?

Reply 3

Super199

OP

20

Original post by Super199

How did you know that? Why cant it be y=1?

Ah not to worry got it

Reply 4

Zacken

22

Original post by Super199

How did you know that? Why cant it be y=1?

Because the gradient of the normal is undefined. Does the horizontal line y=1 have an undefined gradient? (hint: no it has zero gradient), a vertical line has a undefined gradient.

Reply 5

Super199

OP

20

Original post by Zacken

Because the gradient of the normal is undefined. Does the horizontal line y=1 have an undefined gradient? (hint: no it has zero gradient), a vertical line has a undefined gradient.

Yh cheers man got it :smile:

Reply 6

B_9710

18

Original post by Zacken

Because the gradient of the normal is undefined. Does the horizontal line y=1 have an undefined gradient? (hint: no it has zero gradient), a vertical line has a undefined gradient.