derivatives

[tawny moon]

how do i start

[vapid harness]

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[tawny moon]

HINTS PLEASEEE

[turbid bane]

What's a normal?

@tawny moon

[tawny moon]

A normal is a line perpendicular to the tangent

[turbid bane]

So what do you need to know?

[tawny moon]

need to know its slope, and a point

[turbid bane]

And how do you get those?

[tawny moon]

substitute t=2 in the parameters to get the point where the normal is to be found

[turbid bane]

Okay.

[tawny moon]

how do I get the slope?

[turbid bane]

How do you get the slope?

Generally?

[tawny moon]

by differentiating the curve

we get slope of tangent

once that is found normals slope is just negative reciprocal of it

[turbid bane]

Right.

So what happens if we take the derivative of x = t^2? What do we get?

[tawny moon]

w.r.t t?

OHHH

[turbid bane]

...so what do we get?

[tawny moon]

then by chain rule we can get dy/dx
its 2t

[turbid bane]

...no.

We get dx/dt.

dy/dt is when we do the same thing to y = 2t.

[tawny moon]

right

[turbid bane]

And then what do we want?

[tawny moon]

dx/dt =2t
dy/dt=2

dy/dx=1/t

we want -dx/dt

[turbid bane]

Right. dy/dx = (dy/dt)/(dx/dt).

[turbid bane]

...no, we don't.

[tawny moon]

oh i wrote it wrong again.sorry

i meant -dx/dy

the normals slope

[turbid bane]

Which in this case equals?

[tawny moon]

-2

[turbid bane]

So then the equation of our normal is what?

[tawny moon]

2x+y-12 =0

got itt

thank you so much :))

[turbid bane]

No problem.

[tawny moon]

+close