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2 years ago

Given f(x) = 5x – 3, find f(2).

Mathematics

1 answer:

harkovskaia [24]2 years ago

8 0

Answer:

f(2) = 7

Step-by-step explanation:

To figure this out you just have to plug in 2 wherever x is in the equation.

f(2) = 5(2) - 3

Multiply 5 by 2

f(2) = 10 - 3

Subtract

f(2) = 7

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Let f={(-1, 4),(1, 9),(4, 0)} and g={(-1, -8),(2, -7),(4, 8),(5, -9)}. Find g/f and state its domain.

tekilochka [14]

Answer:

g/f = {(-1, 2)}

domain of g/f = {-1}

Step-by-step explanation:

Given,

f = {(-1, 4),(1, 9),(4, 0)},

g = {(-1, -8),(2, -7),(4, 8),(5, -9)}

So, Domain of f = {-1, 1, 4},

Domain of g = {-1, 2, 4, 5}

Since,

$\frac{g}{f}(x) = \frac{g(x)}{f(x)}$

Thus, domain of g/f = Domain of f ∩ Domain of g = {-1, 4}

If x = -1,

$\frac{g}{f}(-1) = \frac{g(-1)}{f(-1)}=\frac{-8}{-4}=2$

If x = 4,

$\frac{g}{f}(4) = \frac{g(4)}{f(4)}=\frac{8}{0}=\infty (\text{ not possible})$

Hence, the domain of g/f = {-1}

And, g/f = {(-1, 2)}

4 0

2 years ago

55.8 is 62% of what number?

zhenek [66]

90

55.8 /? = 62/100
55.8 x 100= 62 x ?
5580=62 x ?
5580/62 = ?
?=90

7 0

2 years ago

Which polygon has an interior angle sum of 1080

Crank

Octagon has 8 sides so the sum of the angles of the octagon is 180(8-2)=180 (6)=1080 degrees

5 0

2 years ago

Read 2 more answers

The product of two whole numbers is 891 and their sum is 60 , what is the two numbers

Rus_ich [418]

Answer:

33 & 27

I am positive !!!!!!!!!!!!

4 0

2 years ago

Use lagrange multipliers to find the point on the plane x â 2y + 3z = 6 that is closest to the point (0, 2, 4).

Arisa [49]

The distance between a point $(x,y,z)$ on the given plane and the point (0, 2, 4) is

$\sqrt{f(x,y,z)}=\sqrt{x^2+(y-2)^2+(z-4)^2}$

but since $\sqrt{f(x,y,z)}$ and $f(x,y,z)$ share critical points, we can instead consider the problem of optimizing $f(x,y,z)$ subject to $x-2y+3z=6$ .

The Lagrangian is

$L(x,y,z,\lambda)=x^2+(y-2)^2+(z-4)^2+\lambda(x-2y+3z-6)$

with partial derivatives (set equal to 0)

$L_x=2x+\lambda=0\implies x=-\dfrac\lambda2$
$L_y=2(y-2)-2\lambda=0\implies y=2+\lambda$
$L_z=2(z-4)+3\lambda=0\implies z=4-\dfrac{3\lambda}2$
$L_\lambda=x-2y+3z-6=0\implies x-2y+3z=6$

Solve for $\lambda$ :

$x-2y+3z=-\dfrac\lambda2-2(2+\lambda)+3\left(4-\dfrac{3\lambda}2\right)=6$
$\implies2=7\lambda\implies\lambda=\dfrac27$

which gives the critical point

$x=-\dfrac17,y=\dfrac{16}7,z=\dfrac{25}7$

We can confirm that this is a minimum by checking the Hessian matrix of $f(x,y,z)$ :

$\mathbf H(x,y,z)=\begin{bmatrix}f_{xx}&f_{xy}&f_{xz}\\f_{yx}&f_{yy}&f_{yz}\\f_{zx}&f_{zy}&f_{zz}\end{bmatrix}=\begin{bmatrix}2&0&0\\0&2&0\\0&0&2\end{bmatrix}$

$\mathbf H$ is positive definite (we see its determinant and the determinants of its leading principal minors are positive), which indicates that there is a minimum at this critical point.

At this point, we get a distance from (0, 2, 4) of

$\sqrt{f\left(-\dfrac17,\dfrac{16}7,\dfrac{25}7\right)}=\sqrt{\dfrac27}$

8 0

2 years ago