Unit tangent vectors: Find the unit tangent vector for the given function at the specified value of t.

r(t)=t,αsinβt,αcosβt,t=0

Short Answer

Expert verified

Ans: The unit tangent vector to t,αsinβt,αcosβtat t=0is11+α2β2,αβ1+α2β2,0

Step by step solution

01

Step 1. Given information:

r(t)=t,αsinβt,αcosβt,t=0

02

Step 2. Simplifying the Unit tangent vectors :

Consider r(t)=t,αsinβt,αcosβt

First, we compute r'(t)

r'(t)=ddtt,αsinβt,αcosβt=1,αβcosβt,-αβsinβtr'(t)=(1)2+(αβcosβt)2+(-αβsinβt)2=1+α2β2

03

Step 3. Finding the Unit tangent vectors: 

The unit tangent vector to r(t)is

T(t)=r'(t)r'(t)=1,αβcosβt,-αβsinβt1+α2β2

At t=0, the unit tangent vector to r(t)is

T(0)=1,αβcos0,-αβsin01+α2β2=1,αβ,01+α2β2=11+α2β2,αβ1+α2β2,0

Thus the unit tangent vector to t,αsinβt,αcosβtat t=0is11+α2β2,αβ1+α2β2,0

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