The Answer of <span>−2cos2π91 =</span> is -2
Insert x = 7
so 3/(7+2) - sqr (7-3)
=3 / (9) - sqr (4)
= 1/3 - 2
=1/3 - 6/3
= -5/3
The answer is y=207 hope this helps
Answer
According to newton law of cooling

and

now At Ta = 100
T₀ = 10 °C
T₁ = 12° C

10 = C + 100
C = -90
now,



at time equal to t
T(t) = 70



t = 48.88 s
hence, after 48.88 s the temperature of the body will be 70°C
b) time taken to reach 98°C



t = 390 s
hence, after 390 s the temperature of the body will be 98°C
He gets paid 24 dollars an hour 960/40=24