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3 years ago

Is the difference of two positive rational number always positive? Explain

Mathematics

1 answer:

Ksenya-84 [330]3 years ago

5 0

No, if you are subtracting a bigger than the one it is being taken from then the answer will be negative. Ex:5-10=-5

Hope this helps:)

You might be interested in

Martha can complete 15 activities a day at summer camp she can choose between crafts and sports

choli [55]

Answer:

15x2=30 combinations

Or x= activities a day

Y=crafts and sports

D=combinations

XxY=D

Step-by-step explanation: variables would be the activities per day and options of what to do. Multiply those to end up with the total number of combinations.

5 0

3 years ago

Express 3(x - 2)2 – 2(x - 1) as an equivalent trinomial.

marta [7]

Answer:

answer is like that that is maybe uncorrect i dont know im not sure

3 0

4 years ago

For each vector field f⃗ (x,y,z), compute the curl of f⃗ and, if possible, find a function f(x,y,z) so that f⃗ =∇f. if no such f

butalik [34]

$\vec f(x,y,z)=(2yze^{2xyz}+4z^2\cos(xz^2))\,\vec\imath+2xze^{2xyz}\,\vec\jmath+(2xye^{2xyz}+8xz\cos(xz^2))\,\vec k$

Let

$\vec f=f_1\,\vec\imath+f_2\,\vec\jmath+f_3\,\vec k$

The curl is

$\nabla\cdot\vec f=(\partial_x\,\vec\imath+\partial_y\,\vec\jmath+\partial_z\,\vec k)\times(f_1\,\vec\imath+f_2\,\vec\jmath+f_3\,\vec k)$

where $\partial_\xi$ denotes the partial derivative operator with respect to $\xi$ . Recall that

$\vec\imath\times\vec\jmath=\vec k$

$\vec\jmath\times\vec k=\vec i$

$\vec k\times\vec\imath=\vec\jmath$

and that for any two vectors $\vec a$ and $\vec b$ , $\vec a\times\vec b=-\vec b\times\vec a$ , and $\vec a\times\vec a=\vec0$ .

The cross product reduces to

$\nabla\times\vec f=(\partial_yf_3-\partial_zf_2)\,\vec\imath+(\partial_xf_3-\partial_zf_1)\,\vec\jmath+(\partial_xf_2-\partial_yf_1)\,\vec k$

When you compute the partial derivatives, you'll find that all the components reduce to 0 and

$\nabla\times\vec f=\vec0$

which means $\vec f$ is indeed conservative and we can find $f$ .

Integrate both sides of

$\dfrac{\partial f}{\partial y}=2xze^{2xyz}$

with respect to $y$ and

$\implies f(x,y,z)=e^{2xyz}+g(x,z)$

Differentiate both sides with respect to $x$ and

$\dfrac{\partial f}{\partial x}=\dfrac{\partial(e^{2xyz})}{\partial x}+\dfrac{\partial g}{\partial x}$

$2yze^{2xyz}+4z^2\cos(xz^2)=2yze^{2xyz}+\dfrac{\partial g}{\partial x}$

$4z^2\cos(xz^2)=\dfrac{\partial g}{\partial x}$

$\implies g(x,z)=4\sin(xz^2)+h(z)$

Now

$f(x,y,z)=e^{2xyz}+4\sin(xz^2)+h(z)$

and differentiating with respect to $z$ gives

$\dfrac{\partial f}{\partial z}=\dfrac{\partial(e^{2xyz}+4\sin(xz^2))}{\partial z}+\dfrac{\mathrm dh}{\mathrm dz}$

$2xye^{2xyz}+8xz\cos(xz^2)=2xye^{2xyz}+8xz\cos(xz^2)+\dfrac{\mathrm dh}{\mathrm dz}$

$\dfrac{\mathrm dh}{\mathrm dz}=0$

$\implies h(z)=C$

for some constant $C$ . So

$f(x,y,z)=e^{2xyz}+4\sin(xz^2)+C$

3 0

4 years ago

Two trains depart Charlotte at the same time!

Furkat [3]

Answer:

The distance between them are increasing with 60+40=100 mph

In an hour distance between them are 100 mph

After 4,5 hours the distance will be 4,5 *100 miles= 450 miles

Step-by-step explanation:

5 0

3 years ago

Solve the following system of equations using the substitution method.

Novay_Z [31]

X=2y
2x+5y=9

substitute the x=2y into the second equation
2(2y)+5y=9
multiple the 2y by 2. 4y+5y=9
combine like terms. 9y=9
divide the 9 out from both sides. y=1
plug the y back into the first equation
x=2(1)
multiply. x=2

your answer is: x=2
y=1

7 0

3 years ago