A certain number is added to four result is double

Drinks at the fair cost 2.50$ use an equation to represent the relationship between the numbers of drinks bought ad the cost def

vodomira [7]

C=5/2*d where c-cost. d-drink

5 0

3 years ago

Read 2 more answers

If x=3+root8 and y =3- root 8 find 1/x^2+1/y^2

KonstantinChe [14]

Answer:

34

Step-by-step explanation:

x=3+√8

y =3-√8

now,

1/x^2+1/y^2

=1/(3+√8)² + 1/(3-√8)²

= [(3-√8)²+(3+√8)²] / (3+√8)²(3-√8)² [L.C.M = (3+√8)²(3-√8)² ]

=[(3-√8+3+√8)²-2(3-√8)(3+√8) ] / [(3+√8)(3-√8)]²

=[6²-2.(3²-√8² )] / (3²-√8²)² [ a²+ b²=(a+b)²-2ab]

=[36-2(9-8) ]/ (9-8)²

=[36-2.1] / 1²

=34

3 0

2 years ago

Find the absolute maximum and absolute minimum values of the function f(x, y) = x 2 + y 2 − x 2 y + 7 on the set d = {(x, y) : |

dsp73

Looks like $f(x,y)=x^2+y^2-x^2y+7$ .

$f_x=2x-2xy=0\implies2x(1-y)=0\implies x=0\text{ or }y=1$

$f_y=2y-x^2=0\implies2y=x^2$

If $x=0$ , then $y=0$ - critical point at (0, 0).
If $y=1$ , then $x=\pm\sqrt2$ - two critical points at $(-\sqrt2,1)$ and $(\sqrt2,1)$

The latter two critical points occur outside of $D$ since $|\pm\sqrt2|>1$ so we ignore those points.

The Hessian matrix for this function is

$H(x,y)=\begin{bmatrix}f_{xx}&f_{xy}\\f_{yx}&f_{yy}\end{bmatrix}=\begin{bmatrix}2-2y&-2x\\-2x&2\end{bmatrix}$

The value of its determinant at (0, 0) is $\det H(0,0)=4>0$ , which means a minimum occurs at the point, and we have $f(0,0)=7$ .

Now consider each boundary:

If $x=1$ , then

$f(1,y)=8-y+y^2=\left(y-\dfrac12\right)^2+\dfrac{31}4$

which has 3 extreme values over the interval $-1\le y\le1$ of 31/4 = 7.75 at the point (1, 1/2); 8 at (1, 1); and 10 at (1, -1).

If $x=-1$ , then

$f(-1,y)=8-y+y^2$

and we get the same extrema as in the previous case: 8 at (-1, 1), and 10 at (-1, -1).

If $y=1$ , then

$f(x,1)=8$

which doesn't tell us about anything we don't already know (namely that 8 is an extreme value).

If $y=-1$ , then

$f(x,-1)=2x^2+8$

which has 3 extreme values, but the previous cases already include them.

Hence $f(x,y)$ has absolute maxima of 10 at the points (1, -1) and (-1, -1) and an absolute minimum of 0 at (0, 0).

3 0

2 years ago

Write a function rule that represents each sentence.1. y is 5 less than the product of 4 and x. 2. 2.5 more than the quotient of

Mrac [35]

1. It is important to go through each of the words given in the question to get through to the actual answer. The function will be:
y= (4 * x) - 5
= 4x - 5

2. The function of this statement will be
(h/3) + 2.5 = w

1. Let us assume the price of a pizza = p
From the first part we can write
p = $6.95
On adding the price of each topping "t" we get
p = $6.95 + ($0.95) * t
= <span>$6.95 + $0.95t</span>
I hope it helps you.

6 0

2 years ago

Is y = -0.375x + 16.625 a linear equation?

Ulleksa [173]

Answer:

Step-by-step explanation:

Yes as the x term is to the first power and is not raised to a larger exponent.

7 0

2 years ago

A certain number is added to four result is double​

A certain number is added to four result is double