<h2>9.</h2><h3>Given</h3>
<h3>Find</h3>
- linear approximation to the volume when the radius increases 0.4 cm
<h3>Solution</h3>
The equation for volume of a sphere is
... V = (4/3)π·r³
Differentiating gives
... dV = 4π·r²·dr
Filling in the given numbers gives
... change in volume ≈ 4π·(15 cm)²·(0.4 cm)
... = 360π cm³ ≈ 1130.97 cm³ . . . . . . volume of layer 4mm thick
<h2>11.</h2><h3>Given</h3>
- an x by x by 2x cuboid with surface area 129.6 cm²
- rate of change of x is 0.01 cm/s
<h3>Find</h3>
<h3>Solution</h3>
The area is that of two cubes of dimension x joined together. The area of each such cube is 6x², but the two joined faces don't count in the external surface area. Thus the area of the cuboid is 10x².
The volume of the cuboid is that of two cubes joined, so is 2x³. Then the rate of change of volume is
... dV/dt = (d/dt)(2x³) = 6x²·dx/dt
We know x² = A/10, where A is the area of the cuboid, so the rate of change of volume is ...
... dV/dt = (6/10)A·dx/dt = 0.6·(129.6 cm²)(0.01 cm/s)
... dV/dt = 0.7776 cm³/s
Answer:
x^2 - 5x = 14
x^2 - 5x-14 = 0
Now, we have to find the multiples of -14 and numbers that add/subtract to -5; this helps to find the factors.
-7+2 = -5
-7*2 = -14
Based on the above info, we can find out my factors; they are:-
(x-7)(x+2)
Answer:
C, f(x) = 2x + 6
Step-by-step explanation:
First, we need to plug in the values of the x coordinates and see if it matches with the y coordinate to determine if it is on the same line. Startin with 2x + 8, we have the point (1, 8) on the graph. Plugging in 1 gets you 10 for the y. This is wrong since 8 is the y coordinate. Moving on, we have 6.4(1.25)^x for the same point. Plugging in 1, we have 6.4 * 1.25 = 8, which is true. Moving on to the second point, (2, 10), we have 1.25 squared times 6.4. This is thus wrong. So, moving on to 2x + 6, we have the point (1, 8), and plugging in 1 for x, we have 8 as y. Since this satisfies the equation we move on to the next point, (2,10). Plugging in x, we have 2 * 2 + 6 = 10, which is also true. Moving on to our third point (3 , 12), we plug in 3 for x. We then get 3 * 2 + 6 = 12, which is correct. This, is our answer then.
Answer:
B and C
if n=3 then 5ⁿ=5³=5×5×5=125
n³=3³=3×3×3=27
hope it helps :)
Answer:
a.114.4kg
b. 486kg
Step-by-step explanation:
Firstly , we want to know the value with which the apples weigh more than the oranges
To calculate this, we simply subtract the weight of the oranges from that of the apple
Mathematically, that would be ;
300.2-185.8 = 114.4kg
The total weight of the things bought is calculated by adding both weights together
That would be 185.8 + 300.2 = 486 kg
