Question

Let p= sin t i + cost j + tk, What is |dp/dt|?
a.\\(\\sqrt(7)\\)
b.\\(\\sqrt(2)\\)
c.\\(\\sqrt(3)\\)
d.\\(\\sqrt(5)\\)

Answer 1

$\frac{dp}{dt}=costi-sintj+k$

$|\frac{dp}{dt}|=\sqrt{cos^2t+sin^2t+1}=\sqrt{2}$

Var. b.