Answer:
y = -9
Step-by-step explanation:
y2 - y1 / x2 - x1
-9 - (-9) / -3 - 1
0 / -4
y = 0 + b
-9 = b
<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:
-1
Step-by-step explanation:
Answer:
The length of each side of the city is 250b
Step-by-step explanation:
Given
--- tree distance from north gate
--- movement from south gate
--- movement in west direction from (b)
See attachment for illustration
Required
Find x
To do this, we have:
--- similar triangles
So, we have the following equivalent ratios
Where:
Substitute these in the above equation
Express as fraction
Cross multiply
Open bracket
Rewrite as:
Expand
Factorize
Factor out x + 284
Split
Solve for x
x can't be negative;
So:
The solution to a system of equations is the point where the 2 lines of a graph cross each other.
On the pictured graph, the lines cross each other at x = -6 and Y = -2.
The answer would be (-6,-2)