Information about concavity is contained in the second derivative of a function. Given f(x) = ax² + bx + c, we have
f'(x) = 2ax + b
and
f''(x) = 2a
Concavity changes at a function's inflection points, which can occur wherever the second derivative is zero or undefined. In this case, since a ≠ 0, the function's concavity is uniform over its entire domain.
(i) f is concave up when f'' > 0, which occurs when a > 0.
(ii) f is concave down when f'' < 0, and this is the case if a < 0.
In Mathematica, define f by entering
f[x_] := a*x^2 + b*x + c
Then solve for intervals over which the second derivative is positive or negative, respectively, using
Reduce[f''[x] > 0, x]
Reduce[f''[x] < 0, x]
1/4 (6 + s)
One-fourth (1/4) of the sum (+) of: 6 and s (6 + s)
Answer:
(3,-4)
Step-by-step explanation:
Answer:
so the answer will be 1
Step-by-step explanation:
An oil tanker can be emptied by the main pump in 5 hours.
An auxilary pump can empty the tanker in 14 hours.
If the main pump is started at 7pm, when should the auxilary pump be started
so that the tanker is emptied by 11pm?
:
Let t = no. of hrs to run the Aux pump
:
The main pump will run 4 hr (7 - 11 pm)
:
Let the completed job = 1; (an empty Tanker)
:
The shared work equation
4%2F5 + t%2F14 = 1
Multiply equation by 70 to get rid of the equation, results:
14(4) + 5t = 70
56 + 5t = 70
5t = 70 - 56
5t = 14
t = 14%2F5
t = 2.8 hrs to run the aux pump
:
2.8 hr = 2 + .8(60) = 2 hrs 48 min
:
Subtract 2:48 from 11:00 = 8:12 PM start the aux pump
;
;
Check solution
4/5 + 2.8/14 =
.8 + .2 = 1
Answer:
Danny does
Step-by-step explanation: 40 / 4 = 10
85 / 5 = 17
10 is less than 17 meaning that Danny is offering a better deal.
Hope this helps!
