Answer::C. d < 2
Step-by-step explanation:
Y=x^3+4 because if you mulitiply x 3 times and then add it by 4 then you should get y
<span>the particle's initial position is at t=0, x = 0 - 0 + 4 = 4m
velocity is rate of change of displacement = dx/dt = d(t^3 - 9t^2 +4)/dt
= 3t^2 - 18t
acceleration is rate of change of velocity = d(3t^2 -18t)/dt
= 6t - 18
</span><span>the particle is stationary when velocity = 0, so 3t^2 - 18t =0
</span>3t*(t - 6) = 0
t = 0 or t = 6s
acceleration = 6t - 18 = 0
t = 3s
at t = 3s, velocity = 3(3^2) -18*3 = -27m/s
displacement = 3^3 - 9*3^2 +4 = -50m
Answer: Alvin = 42 yrs , Elga = 21 yrs
Step-by-step explanation:
Let Elga's age be x , and Alvin's age be y ,since Alvin is two times Elga's age , then
Alvin's age = 2x , that is
y = 2x ............... equation 1
The sum of their ages is 63 implies
x + y = 63 .............. equation 2
Solving the resulting linear equations by substitution method.
Substitute equation 1 into equation 2 , we have
x + 2x = 63
3x = 63
x = 63/3
x = 21
Therefore : Elga is 21 years old , then Alvin will be 21 x 2, which will be 42
