Find the Unit Tangent Vector $\mathbf { T } ( t )$

question 33

Multiple Choice

Find the unit tangent vector $\mathbf { T } ( t )$ for $\mathbf { r } ( t ) = 2 t \mathbf { i } + 6 t \mathbf { j } + 3 t \mathbf { k }$ at $t = - 1$

• A) \(- 2 \mathbf { i } - 6 \mathbf { j } - 3 \mathbf { k }\)
• B) \(\frac { 2 } { 7 }\) i + \(\frac { 6 } { 7 }\) j + \(\frac { 3 } { 7 }\) k
• C) \(- \frac { 2 } { 49 }\) i \(- \frac { 6 } { 49 }\) j \(- \frac { 3 } { 49 }\) k
• D) \(2 \mathbf { i } + 6 \mathbf { j } + 3 \mathbf { k }\)

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