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Mathematics 7 Online
OpenStudy (itz_sid):

HELP PLEASE!

OpenStudy (itz_sid):

I am having trouble with #2. @zepdrix @sweetburger @518nad

OpenStudy (518nad):

slope = dy/dx point = (1-1^-1,7+1^2)

OpenStudy (518nad):

(dy/dt)/(dx/dt) = dy/dx

OpenStudy (itz_sid):

Eh. It's telling me that answer is wrong :/

OpenStudy (itz_sid):

How did you get those points? and why didn't you take a derivative?

OpenStudy (mathmale):

Please, would you share what you yourself have already done? Here you're working with parametric equations. In this case the slope of the tangent line is given by \[\frac{ \frac{ dy }{ dt } }{ \frac{ dx }{ dt}}=\frac{ dy }{ dx }\]

OpenStudy (mathmale):

Have you been able to calculate this derivative? If so, let t=1 and figure out the particular slope for that parameter value. Go back to the original equations for x and y and calculate their values at t=1. This will give you a point on the curve. From this point onward, just use the coordinates of the point and the slope to find the equation of the tangent line. Use the point-slope form of this equation to start with.

OpenStudy (518nad):

i did typo it shud be 1+1^-2 not 2

OpenStudy (518nad):

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OpenStudy (itz_sid):

This is what I did, but got the answer wrong.

OpenStudy (itz_sid):

@mathmale

OpenStudy (518nad):

http://prntscr.com/df2xd4

OpenStudy (518nad):

and oops.. i dunno why i wasnt getting rid of the constand in taking derivative ;)

OpenStudy (itz_sid):

Oh right.... Haha, I made a boo boo mistake. :/

OpenStudy (518nad):

(2t)/(1+t^-2) t=1 (2)/(1+1^-2)= 1 y=x+8

OpenStudy (triciaal):

still open?

OpenStudy (itz_sid):

Wait, so then the slop would be 2/0. Isnt that undefined?

OpenStudy (itz_sid):

@triciaal Sort of, just making silly mistakes.

OpenStudy (itz_sid):

Wouldn't the slope be... \[\frac{ dy }{ dx} = \frac{ 2t }{ 1-\frac{ 1 }{ t^2 } }= \frac{ 2(1) }{ 1-\frac{ 1 }{ (1)^2 } }= \frac{ 2 }{ 0 }\]

OpenStudy (itz_sid):

Wait.... nevermind. I got it.... Thanks!

OpenStudy (triciaal):

ok great

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