(a) If there is a scalar function f(x, y) such that ∇ f(x, y) = x² i + y² j, then
∂f/∂x = x²
∂f/∂y = y²
Integrating both of these equations with respect to x and y (respectively) gives
f(x, y) = 1/3 x³ + g(y)
f(x, y) = 1/3 y³ + h(x)
Differentiating with respect to the other variable gives
∂f/∂y = g'(y) = y²
∂f/∂x = h'(x) = x²
so it follows that
f(x, y) = 1/3 x³ + 1/3 y³ + C
for some constant C.
(b) By the gradient theorem,
Answer:
D. She used the beach's ball's diameter when she should have used the radius
Step-by-step explanation:
To find the volume of the beach ball, using the volume of a sphere is the right formula to use, which is ⁴/3πr³.
The formula she used is correct.
Since the diameter of the ball is assumed to be 12 inches, what is needed to find the volume is the radius.
Radius (r) = ½(diameter) = ½(12) = 6 in.
This is where Emily made a mistake.
She used the diameter of the beach ball instead of its radius (r) which is needed in the equation.
She should have gotten,
V = ⁴/3(3.14)(6)² = 904.32 cubic inches
Answer:
• No
• Yes
• Yes
• No
Step-by-step explanation:
To determine if the 4 given values of y are solutions to the inequality, start by solving the inequality. Solving an inequality is just like that of an equation, except that the direction of the sign changes when the inequality is divided by a negative number.
-2y +7≤ -5
Subtract 7 on both sides:
-2y≤ -5 -7
-2y≤ -12
Divide by -2 on both sides:
y≥ 6
This means that the solution can be 6 or greater than 6.
-10 and 3 are smaller than 6 and are not a solutions, while 7 and 6 satisfies the inequality and are therefore solutions.
_______
Alternatively, we can also substitute each value of y into the inequality and check if the value is less than or equal to -5.
Here's an example to check if -10 is a solution.
-2y +7≤ -5
When y= -10,
-2y +7
= -2(-10) +7
= 20 +7
= 27
Since 27 is greater than 5, it is <u>not</u> a solution to the inequality.
[Given]
{ x + y = 6
{ x = y + 4
[Plug-in our x value & solve]
[Given] x + y = 6
[ Plug-in] (y + 4) + y = 6
[Distribute] y + 4 + y = 6
[Combine like terms] 2y + 4 = 6
[Subtract 4 from both sides] 2y = 2
[Divide both sides by 2] y = 1
[Answer]
Third option - (5, 1)
-> You do not need to solve for x since this is the only option that has y = 1, but to solve for x we would do y + 4 = 1 + 4 = 5, so this answer fully checks correctly
Have a nice day!
I hope this is what you are looking for, but if not - comment! I will edit and update my answer accordingly. (ノ^∇^)
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- Heather
Answer:
Seven one dollar bills and eight five dollar bills.
Step-by-step explanation:
8 + 7 = 15 bills
8 x 5 = $40
7 x 1 = $7
40 + 7 = $47
47 dollars and 15 bills.
