What is the formula for the magnitude of a velocity vector? (magnitude formula)

The position of a particle is given by: x(t)=t^3 + 4t^2
y(t)=t^4 - t^3
Find the velocity vector when t=1
a) <13,3>
b) <11,1>
c) <1,11>
d) <13, 1>
e) <11,3>

Is the following function a heart or a loop: r=1-cosx

How many petals does the function have: r=2sin3x