We will use double angle identities:
cos (5x ) = sin (10x )
cos (5x ) = 2 cos (5x ) sin ( 5x )
cos ( 5 x) - 2 cos ( 5 x ) sin ( 5x ) = 0
cos ( 5 x ) · [ 1 - 2 sin (5 x) ] = 0
cos ( 5 x ) = 0 or : 1 - 2 sin (5 x) = 0
5 x = π/2 +kπ, k∈Z sin (5 x) = 1/2
x1 = π/10 + kπ/5 5 x = π/6+2kπ , k∈ Z
5 x = 5π/6 +2kπ , k∈ Z
x 2 = π/30 +2kπ/5
x 3 = π/9 + 2kπ/5
First multiply 60 x 6 x 45 = 16,200
Then divide, 16,200/350=46.2857
Answer:
10
Step-by-step explanation:
75c-300=25c+200
-25c -25c
50c-300=200
+300 +300
50c=500
c=10
Answer:
x = 50*e∧ -t/100
Step-by-step explanation:
We assume:
1.-That the volume of mixing is always constant 300 gallons
2.-The mixing is instantaneous
Δ(x)t = Amount in - Amount out
Amount = rate * concentration*Δt
Amount in = 3 gallons/ min * 0 = 0
Amount out = 3 gallons/min * x/ 300*Δt
Then
Δ(x)t/Δt = - 3*x/300 Δt⇒0 lim Δ(x)t/Δt = dx/dt
dx/dt = - x/100
dx/ x = - dt/100
A linear first degree differential equation
∫ dx/x = ∫ - dt/100
Ln x = - t/100 + C
initial conditions to determine C
t= 0 x = 50 pounds
Ln (50) = 0/100 * C
C = ln (50)
Then final solution is:
Ln x = - t/100 + Ln(50) or
e∧ Lnx = e ∧ ( -t/100 + Ln(50))
x = e∧ ( -t/100) * e∧Ln(50)
x = e∧ ( -t/100) * 50
x = 50*e∧ -t/100
D is greater than the original number
