Answer:
there are a total of 20 boys and 30 girls in the choir of 50 students
Step-by-step explanation:
Scale the ratio 2:3. so that the numbers on either side sum to 50 . 2+3=5 , and 50÷5=10 , so we scale our ratio by a factor of 10 . So there are a total of 20 boys and 30 girls in the choir of 50 students
With

we have

The vector field evaluated over this parameterization is

so the line integral is


Answer:
53.3324
Step-by-step explanation:
given that a thermometer is removed from a room where the temperature is 70° F and is taken outside, where the air temperature is 40° F.
By Newton law of cooling we have
T(t) = 
where T (t) is temperature at time t,T =surrounding temperature = 40, T0 =70 = initial temperature
After half minute thermometer reads 60° F. Using this we can find k

So equation is

When t=1,
we get

Answer:
Step-by-step explanation:
Vertex is halfway between focus and directrix, so focus is (-3,0).
Answer:
3
Step-by-step explanation:
To find the rate of change we: divide the change in y (output) by the change in x (input).
A = (-3 - 0) / (0 - 1) = -3 / -1 = 3
:)