# draw curve

• Jan 26th 2011, 07:45 AM
paulaa
draw curve
need help with this one.

draw the curve y^2=2x-1

y=(2x-1)^0.5 x > 1/2

?
• Jan 26th 2011, 08:13 AM
yeKciM
Quote:

Originally Posted by paulaa
need help with this one.

draw the curve y^2=2x-1

y=(2x-1)^0.5 x > 1/2

?

and now just make you'r self table... and get 3 points chose x and get y ... and just connect them ... you have one there its y= 0 in x = 0.5 :D you need just 2 more :D
• Jan 26th 2011, 08:16 AM
paulaa
do you mean like this:

y x
0 0.5
1 1
2 2.5

and then ?
• Jan 26th 2011, 08:24 AM
yeKciM
for x = 0.5 you have y = 0
for x = 1 you have y = (2*1-1)^(1/2) = 1 and also y = -1 :D

so you have 3 points and now just connect them :D your curve goes from x = 0.5 to infinity or less :P so it's moving to the "right" above and belove x axis :D
• Jan 26th 2011, 08:45 AM
paulaa
how do you know that it is to the right ?
• Jan 26th 2011, 09:11 AM
yeKciM
Quote:

Originally Posted by paulaa
how do you know that it is to the right ?

how in detail you need your answer ? Because i don't know for which level do I approach because this is simple curve (parabola) and some curve's like this you get to know .... y = x^2 , -y=x^2 , x = y^2 , -x = y^2 ... and all can be done by 3 points :D or more if you like and connecting them... but if you need to do , region for which function is defined , add or even or neither, sing , asymptote's , first and second derivate... we will do it different :D :D
• Jan 26th 2011, 09:13 AM
paulaa
thz for the answers :)
• Jan 26th 2011, 09:21 AM
yeKciM
you should know also that y = x^2 and y = x^2 -1 or y= x^2 +1 are the same parabola just shifted up or down, left or right depending on which do you have ... y = x^2 have zero in point (x=0,y=0) , and y = x^2 +1 looks the same but have zero in (x=0, y = 1) so it's just shifted upwards by the y axis :D play little and you will have no problem with this type of curves :D
• Jan 26th 2011, 09:22 AM
paulaa
yes i did know that :P but thanks :)