4. For what values of the constant a is the following function concave/convex? f(x, y)= -6x2 + (2a+4)xy-y+4ay
Angles in Circles
Angles within a circle are feasible to create with the help of different properties of the circle such as radii, tangents, and chords. The radius is the distance from the center of the circle to the circumference of the circle. A tangent is a line made perpendicular to the radius through its endpoint placed on the circle as well as the line drawn at right angles to a tangent across the point of contact when the circle passes through the center of the circle. The chord is a line segment with its endpoints on the circle. A secant line or secant is the infinite extension of the chord.
Arcs in Circles
A circular arc is the arc of a circle formed by two distinct points. It is a section or segment of the circumference of a circle. A straight line passing through the center connecting the two distinct ends of the arc is termed a semi-circular arc.
Can you help with question 4?
![..
CHAPTER 2I MULTIVARIABLE CALCULUS
2. (a) Let f be defined for all x, y by f(x, y) x-y - x². Show that f is concave (i) by using
Theorem 2.3.1, (ii) by using Theorem 2.3.4.
(b) Show that -e-Ju.y) is concave.
3. (a) Show that f (x, y) = axr² + 2bxy + cy² + px +qy+r is strictly concave if ac – b² > 0
and a < 0, whereas it is strictly convex if ac - b? > 0 and a > 0.
(b) Find necessary and sufficient conditions for f(x, y) to be concave/convex.
4. For what values of the constant a is the following function concave/convex?
f(x, y) =-6x²+ (2a + 4)xy – y² + 4ay
SM 5. Examine the convexity/concavity of the following functions:
á+x³ – ,? – 6 + x = 2 (x)
(b) z = e*+y + e*=y - }y
(c) w = (x+ 2y + 3z)²
SM 6. Suppose y = f(x) is a production function determining output y as a function of the vector x
of nonnegative factor inputs, with f(0) = 0. Show that:
(a) If f is concave, then f(x) <0 (so each marginal product f{(x) is decreasing).
(b) If f is concave, then f (Ax)/A is decreasing as a function of 2.
(c) If f is homogeneous of degree 1 (constant returns to scale), then f is not strictly concave.
Tat f he defined for all v in R" by f(x) = |x H =./x +...+x². Prove that f is convex. Is
902
BANG
prt sc
delete
home
pua
Bd
wnu
lock
->
backspace
8
[
home
enter
4.
->](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2F3143ece0-b2b2-417b-825f-ab4e468fd03e%2F141c43fa-da26-4e34-8383-01cd1bf4e3b5%2Fekwgkol_processed.jpeg&w=3840&q=75)
![](/static/compass_v2/shared-icons/check-mark.png)
Trending now
This is a popular solution!
Step by step
Solved in 3 steps with 2 images
![Blurred answer](/static/compass_v2/solution-images/blurred-answer.jpg)
![Advanced Engineering Mathematics](https://www.bartleby.com/isbn_cover_images/9780470458365/9780470458365_smallCoverImage.gif)
![Numerical Methods for Engineers](https://www.bartleby.com/isbn_cover_images/9780073397924/9780073397924_smallCoverImage.gif)
![Introductory Mathematics for Engineering Applicat…](https://www.bartleby.com/isbn_cover_images/9781118141809/9781118141809_smallCoverImage.gif)
![Advanced Engineering Mathematics](https://www.bartleby.com/isbn_cover_images/9780470458365/9780470458365_smallCoverImage.gif)
![Numerical Methods for Engineers](https://www.bartleby.com/isbn_cover_images/9780073397924/9780073397924_smallCoverImage.gif)
![Introductory Mathematics for Engineering Applicat…](https://www.bartleby.com/isbn_cover_images/9781118141809/9781118141809_smallCoverImage.gif)
![Mathematics For Machine Technology](https://www.bartleby.com/isbn_cover_images/9781337798310/9781337798310_smallCoverImage.jpg)
![Basic Technical Mathematics](https://www.bartleby.com/isbn_cover_images/9780134437705/9780134437705_smallCoverImage.gif)
![Topology](https://www.bartleby.com/isbn_cover_images/9780134689517/9780134689517_smallCoverImage.gif)