I have a question about Parametric equations in Calculus. How do you go about solving the problem is below?

Question

Parametric equations for the motion of an object are given below, where x and y are measured in meters and t is in seconds. How do you find the speed of the object in meters per second when t is 2 seconds.

x = 6 cos 5t
y = 6 sin 5t

I came up with a solution of 6. I'm not sure if this is correct or not.

these are the possible solutions to choose from....


a. 2

b. 6

c. 10

d. 12

e. 20

f. 30

or none of these

Answer 1

dx/dt=-30sin5t and dy/dt=30 cos5 t
Those are the components of the "velocity vector"
The speed is the modulus of this vector=
sqrt(1800)= 30sqrt2m/s and is constant but the direction of velocity
is NOT constant
x^2+y^2=36 so the object moves on a circunsference

Answer 2

you have the x and y components of the objects' displacement given, so if you differentiate w.r.t "t", you'll get the respective velocity components. Since they are orthogonal, just add the squares of the components and take the root.
NB: As for putting the value of "t", i think you might've missed out the "pi".. So I didn't solve it..