Problem

Find T,N and B for the curve r(t)=3cos(4t),3sin(4t),2t at the point t=0
Give your answers to two decimal places

Answer

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Answer

Final Answer: The unit tangent vector T at t=0 is (0,63737,3737), the unit normal vector N at t=0 is (1,0,0), and the binormal vector B at t=0 is (0,3737,63737)

Steps

Step 1 :Given the curve r(t)=3cos(4t),3sin(4t),2t

Step 2 :Calculate the derivative of r(t) to get r(t)=12sin(4t),12cos(4t),2

Step 3 :Normalize r(t) to get the unit tangent vector T=r(t)||r(t)||=12sin(4t)144sin2(4t)+144cos2(4t)+4,12cos(4t)144sin2(4t)+144cos2(4t)+4,2144sin2(4t)+144cos2(4t)+4

Step 4 :Calculate the derivative of T to get T=48cos(4t)144sin2(4t)+144cos2(4t)+4,48sin(4t)144sin2(4t)+144cos2(4t)+4,0

Step 5 :Normalize T to get the unit normal vector N=T||T||=48cos(4t)2304sin2(4t)+2304cos2(4t),48sin(4t)2304sin2(4t)+2304cos2(4t),0

Step 6 :Calculate the cross product of T and N to get the binormal vector B=T×N=0,3737,63737

Step 7 :Substitute t=0 into T, N, and B to get T(0)=0,63737,3737, N(0)=1,0,0, and B(0)=0,3737,63737

Step 8 :Final Answer: The unit tangent vector T at t=0 is (0,63737,3737), the unit normal vector N at t=0 is (1,0,0), and the binormal vector B at t=0 is (0,3737,63737)

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