Local versus absolute extrema. If you recall from single-variable calculus (calculus I), if a function has only one critical point, and that critical point is a local maximum (or say local minimum), then that critical point is the global/absolute maximum (or say global/absolute minnimum). This fails spectacularly in higher dimensions (and thereís a famous example of a mistake in a mathematical physics paper because this fact was not properly appreciated.) You will compute a simple example in this problem. Let f(x; y) = e 3x + y 3 3yex . (a) Find all critical points for this function; in so doing you will see there is only one. (b) Verify this critical point is a local minimum. (c) Show this is not the absolute minimum by Önding values of f(x; y) that are lower than the value at this critical point. We suggest looking at values f(0; y) for suitably chosen y
Answer:
Step-by-step explanation:
Given that:
a)
[tex]f(x,y) = e^{3x} + y^3 - 3ye^x \\ \\ \implies \dfrac{\partial f}{\partial x} = 0 = 3e^{3x} -3y e^x = 0 \\ \\ e^{2x}= y \\ \\ \\ \implies \dfrac{\partial f}{\partial y } = 0 = 3y^2 -3e^x = 0 \\ \\ y^2 = e^x[/tex]
[tex]\text{Now; to determine the critical point:}[/tex]- [tex]f_x = 0 ; \ \ \ \ \ f_y =0[/tex]
[tex]\implies e^{2x} = y^4 = y \\ \\ \implies y = 0 \& y =1 \\ \\ since y \ne 0 , \ \ y = 1, \ \ x= 0\\\text{Hence, the only possible critical point= }(0,1)[/tex]
b)
[tex]\delta = f_xx, s = f_{xy}, t = f_{yy} \\ \\ . \ \ \ \ \ \ \ \ D = rt-s^2 \\ \\ i) Suppose D >0 ,\ \ \ r> 0 \ \text{then f is minima} \\ \\ ii) Suppose \ D >0 ,\ \ \ r< 0 \ \text{then f is mixima} \\ \\ iii) \text{Suppose D} < 0 \text{, then f is a saddle point} \\ \\ iv) Suppose \ D = 0 \ \ No \ conclusion[/tex]
[tex]Thus \ at (0,1) \\ \\ \delta = f_{xx} = ge^{3x}\implies \delta (0,1) = 6 \\ \\ S = f_{xy} = -3e^x \\ \\ \implies S_{(0,1)} = -3 \\ \\ t = f_{yy} = 6y \\ \\[/tex]
[tex]\implies t_{0,1} = 6[/tex]
[tex]Now; D = rt - s^2 \\ \\ = (6)(6) -(-3)^2[/tex]
[tex]= 36 - 9 \\ \\ = 27 > 0 \\ \\ r>0[/tex]
[tex]\text{Hence, the critical point} \ (0,1) \ \text{appears to be the local minima}[/tex]
c)
[tex]\text{Suppose we chose x = 0 and y = -3.4} \\ \\ \text{Then, we have:} \\ \\ f(0,-3.4) = 1+ (-3.4)^3 + 3(3.4) \\ \\ = -28.104 < -1[/tex]
[tex]\text{However, if f (0,1) = 1 +1 -3 = -1 \\ \\ f(0,-3.4) = -28.104} < -1} \\ \\ \text{This explains that} -1 \text{is not an absolute minimum value of f(x,y)}[/tex]
Suppose that the height (in centimeters) of a candle is a linear function and the amount of time (in hours) it has been burning. After 9 hours of buring, a candle has a hight of 22.2 centimeters. After 23 hours of burning, it's heigh is 16.8 centimeters. What is the height of candle after 19 hour
Answer: cockme
Step-by-step explanation:
cockme
What is the solution set for this inequality?
-8x + 32 -16
x < 6
x > 6
x > -2
x < -2
Answer:
x>-2
Step-by-step explanation:
-8x+32-16<0
-8x<16
divide both sides by -8
x>-2
that's because when you divide by a negative your inequality sign changes
Answer right and you get brainliest
What is the area
The area of a circle is 4 square centimeters. What is the circumference?
c. Translate the follom
4.) 51 - (x+5)
5.) 3(7-8)
Step-by-step explanation:
1. 51-x-5
= 46-x Answer
2. 21-24
= -3 Answer
Nathaniel is using the quadratic formula to solve 0 = x2 + 5x - 6. His steps are shown below/attached
What are solutions to the equations
Answer:
A
Step-by-step explanation:
Answer:
x= -6 ,1
Step-by-step explanation:
B is the answer
x= -6 ,1
Verify the Identity.
tan²xsin²x = tan²x-sin²x
tan²(x) - sin²(x) = sin²(x)/cos²(x) - sin²(x)
… = sin²(x) (1/cos²(x) - 1)
… = sin²(x) (sec²(x) - 1)
… = sin²(x) tan²(x)
How many people ordered beer?
*it is not 15
Answer:
18 people ordered beer.
Step-by-step explanation:
15 + 3 = 18 people
Answer:
18
Step-by-step explanation:
Add the 15 as well as the three people who purchased both wine and beer. The total for beer purchases would be 18.
3. The third side of a triangle measures (3x-5) cm. If the length of the midline is 14 m,
what is x?
A 8
C. 10
B. 9
D. 11
Answer:
D. 11
Step-by-step explanation:
Midsegment theorem:
The length of the midsegment of a triangle is half the length of it's third side.
In this question:
Third side: 3x - 5
Midsegment: 14m
So
[tex]\frac{3x - 5}{2} = 14[/tex]
[tex]3x - 5 = 28[/tex]
[tex]3x = 33[/tex]
[tex]x = \frac{33}{3}[/tex]
[tex]x = 11[/tex]
The correct answer is given by option D.
Find the value of x in the diagram
Answer:
x = 21
Step-by-step explanation:
Based on the inscribed angle theorem, we would have:
120° = 2(3x - 3)°
Solve for x
120 = 2*3x - 2*3
120 = 6x - 6
Add 6 to both sides
120 + 6 = 6x
126 = 6x
Divide both sides by 6
126/6 = x
21 = x
x = 21
C(4,4)
D(-8,0
B(6, -2)
A(-6, -6)
Answer:
I don't know how to do it the subject
6. cory gets paid every two weeks. he works 40 hours per week at $7.75 per hour. cory has the following deductions: 8% for medical insurance, 12% for federal and state taxes, and 10% for retirement. cory's net pay will be $________.
Answer:
$434
Step-by-step explanation:
Gross Pay
$7.75 per hour40 hours per weekPay received every 2 weeks⇒ Total gross pay = 7.75 × 40 × 2 = $620
Deductions
Medical insurance = 8%Taxes = 12%Retirement = 10%⇒ Total deductions = 8% + 12% + 10% = 30%
Net Pay
Net Pay = Total Gross Pay - Total deductions
= $620 - (30% of $620)
= $620 - (0.3 × $620)
= $620 - $186
= $434
Therefore, Cory's net pay will be $434.
Factor out the greatest common monomial factor from polynomial. Show your work or explain your reasoning
Answer:
7(1 +3x)
Step-by-step explanation:
The simplest monomial is a constant that is a prime number. That constant is a factor of the coefficient of the only other monomial in the expression, so it can factored from both terms.
= 7 + 7·3x
= 7(1 +3x)
During the month of April, Samantha Kept
track of the number of days she saw a
hummingbird in her garden. She saw a
hummingbird 18 days during that 30 day
month. Based on this information, how
many days will she see a hummingbird
during the 180 day summer?
Answer:
she will see 108 humming birds
Step-by-step explanation:
30x6= 180
so mutiply how many times she sees one in a month by 6
Answer:
3240
Step-by-step explanation:
Starting point (1, 4) Show me the new coordinates of the point (1, 4) after it is:
Reflected over the line y = x.
Reflected over the line y = −x.
Rotated through 90°clockwise about the origin.
Rotated through 90°counterclockwise about the origin
Step-by-step explanation:
Reflected over the line y=x is (4,1)
Reflected over the line y=-x is (-4,-1)
Rotated through 90 clockwise about the origin is (4,-1)
Rotated through 90 counterclockwise about the origin is(-4,1)
Q: Find six rational numbers between 3 and 4 .
Answer:
Six rational numbers between 3 and 4 are 3.1, 3.2, 3.3, 3.4, 3.5 and 3.6.
Answer:
six rational numbers between 3 and 4 are 227 , 237 , 247 , 257 , 267 , 277
An experiment examined the impact of THC (the active ingredient in marijuana) on various physiological and psychological variables. The study recruited a sample of 18 young adults who were habitual marijuana smokers. Subjects came to the lab 3 times, each time smoking a different marijuana cigarette: one with 3.9% THC, one with 1.8% THC, and one with no THC (a placebo). The order of the conditions was randomized in a double-blind design. At the start of each session, no subject reported being "high." After smoking the cigarette, participants rated how "high" they felt, using a positive continuous scale (0 representing not at all "high"). For the placebo condition, participants reported a mean "high" feeling of 11.3, with a standard deviation of 15.5. A 95% confidence interval for the population mean feeling of "high" after smoking a placebo marijuana cigarette is
Answer:
OOO
Step-by-step explanation:
What is the intercept of the equation
Answer:
-2
Step-by-step explanation:
Plug y=0 into the equation and solve the resulting equation 0=3x+6 for x
i'll give brainliest
reflect (-4,4) in the x-axis
Answer:
(-4,-4)
Step-by-step explanation:
Anytime you reflect a coordinate point across the x-axis, the y-coordinate becomes its opposite and the x-coordinate stays the same.
In this coordinate: (-4,4)
Reflecting (-4,4) across the x-axis means the x-coordinate (-4) would stay the same and the y-coordinate (4) would become its opposite (-4).
The new coordinates after being reflected across the x-axis are (-4,-4).
Find the range for the data. 1480, 1375, 1285, 1740, 1195, 1785, 1710, 1725, 1355, 1890, 1455
Answer:
The range of the data value is 695.
Step-by-step explanation:
Please mark me brainlliest!
Answer:
695
Step-by-step explanation:
Range is the difference between the largest and smallest value.
1480, 1375, 1285, 1740, 1195, 1785, 1710, 1725, 1355, 1890, 1455
1890 - 1195
695
PA = 0.5 PB = 0.3 and p A and b equals 0.15 what is p A or b
Answer:
P(A) = 0.2, P(B) = 0.5, P(A\B) = 0.3:
P(A\B) = P(A and B) P(B)
0.3 = P(A and B) 0.5
0.15 P(A and B)
P(A and B) = 0.15
B. P(A or B) = P(A) + P(B) - P(A and B)
0.2 + 0.5 - 0.15
0.70 - 0.15 = 0.55
Two of the angles in a triangle measure 90 degrees and 7 degrees what is the measure of the third angle
Answer:
The third angle would be 83 degrees.
Step-by-step explanation:
Seeing that every triangle's angles will always add up to 180 degrees, we would do the following:
180-90=90
90-7=83 degrees.
Find the area of the polygon.
The population of a city decreases by 4% per year. If this year's population is 171,000, what will next year's population be, to the nearest individual?
please help and putting the steps would help
Answer:
x = 8
Step-by-step explanation:
These angles provided are alternate interior angles. That means they are congruent (equal). All you need to do now is answer the equation "8x-4 = 60".
From that you can see that x is 8.
Answer:
the angles are alternate interior angle pair, they are equal
8x - 4 = 608x = 64x = 8(3f–3)^2 pls help
aaaaaaaaaaaaaaaaaaaa
a hardware factory produces 3.6 •10^5 bolts in 2400 minutes. what is the factory rate of production in bolts per minute
Gina needs to buy a bathroom mirror that is 3 feet wide and 6 feet long. If the mirror sells for $3.00 per square foot, what will the total cost of the mirror be?
Answer:
$54
Step-by-step explanation:
beacuse 6x3=18 and 18x3=54 so your answer will be $54
sorry if im wrong mark me brainliest if im right
The line passes through the points (3, 7) and (4, 9)
Answer:
I'm confused as to what your asking?
Answer:
y= 2x +1
Step-by-step explanation:
slope 9-7/4-3 = 2/1= 2
y-7 = 2(x -3)
y-7 = 2x -6
y = 2x +1