Answer with explanation:
Let us assume that the 2 functions are:
1) f(x)
2) g(x)
Now by definition of concave function we have the first derivative of the function should be strictly decreasing thus for the above 2 function we conclude that
Now the sum of the 2 functions is shown below
Diffrentiating both sides with respect to 'x' we get
Since each term in the right of the above equation is negative thus we conclude that their sum is also negative thus
Thus the sum of the 2 functions is also a concave function.
Part 2)
The product of the 2 functions is shown below
Diffrentiating both sides with respect to 'x' we get
Now we can see the sign of the terms on the right hand side depend on the signs of the function's themselves hence we remain inconclusive about the sign of the product as a whole. Thus the product can be concave or convex.
Part A.
Ashwin had a 4-cm cube.
volume of cube = side^3
volume = (4 cm)^3 = 64 cm^3
Ashwin has 64 small cubes.
We need to find the volumes of all prisms in Part A. Only prisms with at most 64 cm^3 volume can be the answer.
A. v = 2 * 4 * 7 = 28
B. v = 4 * 5 * 6 = 120
C. v = 5 * 5 * 4 = 100
D. v = 4 * 7 * 5 = 140
E. v = 3 * 5 * 4 = 60
Part A. answer: A, E
Part B.
Dora had a 5-cm cube.
volume of cube = side^3
volume = (5 cm)^3 = 125 cm^3
Dora has 125 small cubes.
We need to find the volumes of all prisms in Part B. Only prisms with at most 125 cm^3 volume can be the answer.
A. v = 3 * 3 * 8 = 72
B. v = 3 * 4 * 5 = 60
C. v = 6 * 6 * 4 = 144
D. v = 5 * 8 * 4 = 160
E. v = 3 * 5 * 4 = 60
Part B. answer: A, B, E
Answer:
30 milk chocolates
Step-by-step explanation:
42 ÷ 7 = 6 - a fraction of the chocolates
6 x 5 = 30 - the milk chocolates (7+5 = 12 which is the whole fraction).
Answer:
- plane: 530 mi/h
- wind: 40 mi/h
Step-by-step explanation:
Let p and w represent the speeds of the plane and the wind. The relation between time, speed, and distance is ...
speed = distance/time
p +w = (2565 mi)/(4.5 h) = 570 mi/h
p -w = (2205 mi)/(4.5 h) = 490 mi/h
Adding these speeds, we get ...
(p +w) +(p -w) = (570) +(490) mi/h
2p = 1060 mi/h
p = 530 mi/h
Then the speed of the wind is ...
w = 570 mi/h -p = (570 -530) mi/h = 40 mi/h
The plane's speed is 530 mi/h; the wind speed is 40 mi/h.
Answer:
A. is incorrect. He has to divide 76 by 19, instead of subtracting 19 to 76.
B. This equation has one solution. v=4
Step-by-step explanation:
Hi, Martin’s answer is incorrect.
A. He has to divide 76 by 19, instead of subtract 19 to 76.
The correct steps are:
19v = 76
Since 19 is multiplying the variable, to eliminate it we have to divide by 19.
v = 76/19
v = 4
B. This equation has one solution. It’s v=4
Feel free to ask for more if needed or if you did not understand something.
