How do I find the speed of an object with a given position function?

[Math10]

Homework Statement

Find the speed of an object with r(t)=e^(t)<cos(t), sin(t), 1>.

Homework Equations

None.[/B]

The Attempt at a Solution

v(t)=e^(t)<cos(t)-sin(t), cos(t)+sin(t), 1>
I know that the speed is abs(v(t)) and the answer in the book is sqrt(3)*e^(t). So how do I find the speed?

 

[Mark44]

Homework Statement

Find the speed of an object with r(t)=e^(t)<cos(t), sin(t), 1>.

Homework Equations

None.[/B]

The Attempt at a Solution

v(t)=e^(t)<cos(t)-sin(t), cos(t)+sin(t), 1>
I know that the speed is abs(v(t)) and the answer in the book is sqrt(3)*e^(t). So how do I find the speed?

The speed is the magnitude of your vector for v(t). How do you usually find the magnitude of a vector?

 

[Math10]

Never mind, I got it! Thanks for helping.