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3 years ago

6

The lengths of the sides of a square are represented by the expression 3x + 1 cm. The perimeter of the square is 28 cm. What is

the value of x

1 answer:

pshichka [43]3 years ago

7 0

Answer:

x=2

Step-by-step explanation:

Perimeter of a square = 4*(side of the square)

28 = 4*(3x+1)

28 = 12x + 4

28- 4 = 12x

24 = 12x

x =2

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If f(x)= x2/x+3, find f(x+h)?

kompoz [17]

f(x+h) = $\frac{x^{2}+2xh+h^{2} }{x+h+3}$

Step-by-step explanation:

Given,

f(x) = $\frac{x^{2} }{x+3}$

To find the value of f(x+h) we need to replace x by x+h

Hence,

f(x+h) = $\frac{(x+h)^{2} }{x+h+3}$

= $\frac{x^{2}+2xh+h^{2} }{x+h+3}$

[Here, we apply the formula of $(a+b)^{2}= a^{2} +2ab+ b^{2}$ ]

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3 years ago

Consider F and C below. F(x, y, z) = y2 sin(z) i + 2xy sin(z) j + xy2 cos(z) k C: r(t) = t2 i + sin(t) j + t k, 0 ≤ t ≤ π (a) Fi

Liono4ka [1.6K]

Answer:

a) $f (x,y,z)= xy^2\sin(z)$

b) $\int_C F \cdot dr =0$

Step-by-step explanation:

Recall that given a function f(x,y,z) then $\nabla f = (\frac{\partial f}{\partial x},\frac{\partial f}{\partial y},\frac{\partial f}{\partial z})$ . To find f, we will assume it exists and then we will find its form by integration.

First assume that F = $\nabla f$ . This implies that

$\frac{\partial f}{\partial x} = y^2\sin(z)$ if we integrate with respect to x we get that

$f(x,y,z) = xy^2\sin(z) + g(y,z)$ for some function g(y,z). If we take the derivative of this equation with respect to y, we get

$\frac{\partial f}{\partial y} = 2xy\sin(z) + \frac{\partial g}{\partial y}$

This must be equal to the second component of F. Then

$2xy\sin(z) + \frac{\partial g}{\partial y}=2xy\sin(z)$

This implies that $\frac{\partial g}{\partial y}=0$ , which means that g depends on z only. So $f(x,y,z) = xy^2\sin(z) + g(z)$

Taking the derivative with respect to z and making it equal to the third component of F, we get

$xy^2\cos(z)+\frac{dg}{dz} = xy^2\cos(z)$

which implies that $\frac{dg}{dz}=0$ which means that g(z) = K, where K is a constant. So

$f (x,y,z)= xy^2\sin(z)$

b) To evaluate $\int_C F \cdot dr$ we can evaluate it by using f. We can calculate the value of f at the initial and final point of C and the subtract them as follows.

$\int_C F \cdot dr = f(r(\pi))-f(r(0))$

Recall that $r(\pi) = (\pi^2, 0, \pi)$ so $f(r(\pi)) = \pi^2\cdot 0 \cdot \sin(\pi) = 0$

Also $r(0) = (0, 0, 0)$ so $f(r(0)) = 0^2\cdot 0 \cdot \sin(0) = 0$

So $\int_C F \cdot dr =0$

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3 years ago

Margo spends 0.25 of her paycheck on a new dress, 1/8 of her paycheck on shoes, and $24 on a birthday present. If she spent $60

horsena [70]

Margos paycheck was $96 in total

8 0

3 years ago

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Find all real solutions:<br> x² - x - 12 = 0

Andrej [43]

Factor the equation. Remember the value should add to the b value and multiply to the c value.

x^2-x-12= 0
(x-4)(x+3)=0

Use the zero product property to find roots
x-4=0
x=4

x+3=0
x=-3

Final answer: x=-3, x=4

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3 years ago

11/18% of a quantity is equal to what fraction of the quantity?

Burka [1]

Answer:

22/36

Step-by-step explanation:

11 × 2

18 × 2

= 22/36

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2 years ago

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