Answer:
-1 -+i/5/2
Step-by-step explanation:
tangent 60 is √3 on the unit circle and tangent 225 is 1. So 1+√3 is the exact value of tan 60 plus tan 225
B. -3 and 5
constants are the numbers without variables (the letters) and coefficients are the numbers with variables
Answer:
9 hours
Step-by-step explanation:
According to Newton's laws of cooling
dT/dt = -k(T - A)
Let U = T - A
dU/dT = 1
dU = dT
dt/dt = -kU
dT = -kU(dt)
dU/U = -kdt
On integration
ln(U) = -kt + C
U = Ce^-kt
T - A = Ce^-kt
T(0) = 68
T(5) = 25
68 - 20 = Ce^-k(0)
C = 48
and
25 -20 = 48e^-k(5)
5 = 48e^-5k
e^-5k = 5/48
-5k = ln (5/48)
k = - ln(5/48) / 5
k = - 0.4524
T - 20 = 48e^-0.4524t
When T = 21
21 -20 = 48e^-0.4524t
1 = 48e^-0..4524t
e^-0.4524t = 1/48
-0.4524t = ln (1/48)
t = - ln(1/48) / 0.4524
t = 8.5570
t= 9 hours ( to the nearest hour)
I'm pretty sure that you multiply 10x by 6. Since it is length by width those are the length and the width.
Glad I could help!
