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2 years ago

Fine the sum of 2/9+3/5

Mathematics

1 answer:

Arturiano [62]2 years ago

6 0

Answer:

0.82

اولويات الضرب و القسمه

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9<br> Write as a percentage.<br> 10

Ludmilka [50]

Answer:

Step-by-step explanation:

I really dont know but if I did I would say I'm a 6 grader

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3 years ago

Four sets of three squared

yKpoI14uk [10]

Answer:

$4^3$

Step-by-step explanation:

Four sets of three Squared

To start, you will need to get the set(base number) and get the exponent 3 and put it on the top.

$4^3$

Hope this helps!

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2 years ago

All vectors are in Rn. Check the true statements below:

Oduvanchick [21]

Answer:

A), B) and D) are true

Step-by-step explanation:

A) We can prove it as follows:

$Proy_{cv}y=\frac{(y\cdot cv)}{||cv||^2}cv=\frac{c(y\cdot v)}{c^2||v||^2}cv=\frac{(y\cdot v)}{||v||^2}v=Proy_{v}y$

B) When you compute the product Ax, the i-th component is the matrix of the i-th column of A with x, denote this by Ai x. Then, we have that $||Ax||=\sqrt{(A_1 x)^2+\cdots (A_n x)^2}$ . Now, the colums of A are orthonormal so we have that (Ai x)^2=x_i^2. Then $||Ax||=\sqrt{(x_1)^2+\cdots (x_n)^2}=||x||$ .

C) Consider $S=\{(0,2),(2,0)\}\subseteq \mathbb{R}^2$ . This set is orthogonal because $(0,2)\cdot(2,0)=0(2)+2(0)=0$ , but S is not orthonormal because the norm of (0,2) is 2≠1.

D) Let A be an orthogonal matrix in $\mathbb{R}^n$ . Then the columns of A form an orthonormal set. We have that $A^{-1}=A^t$ . To see this, note than the component $b_{ij}$ of the product $A^t A$ is the dot product of the i-th row of $A^t$ and the jth row of $A$ . But the i-th row of $A^t$ is equal to the i-th column of $A$ . If i≠j, this product is equal to 0 (orthogonality) and if i=j this product is equal to 1 (the columns are unit vectors), then $A^t A=I$

E) Consider S={e_1,0}. S is orthogonal but is not linearly independent, because 0∈S.

In fact, every orthogonal set in R^n without zero vectors is linearly independent. Take a orthogonal set $\{u_1,u_2\cdots u_p\}$ and suppose that there are coefficients a_i such that $a_1u_1+a_2u_2\cdots a_nu_n=0$ . For any i, take the dot product with u_i in both sides of the equation. All product are zero except u_i·u_i=||u_i||. Then $a_i||u_i||=0$ then $a_i=0$ .

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3 years ago

Suppose that 1 kg of Sodium-24 is reduced to 0.0156 kg in 90 hours. What is the half-life, in hours, of Sodium-24?

N76 [4]

Answer:

14.99 hours

Step-by-step explanation:

The formula for half-life is given as,

R/R' = 2ᵃ/ᵇ...................... Equation 1

Where R= Original mass of sodium-24, R' = mass of Sodium-24 after disintegration, a = Total time taken for sodium-24 to disintegrate, b = half-life of sodiun-24.

Given: R = 1 kg, R' = 0.0156 kg, a = 90 hours

Substitute into equation 1 and solve for b

1/(0.0156) = 2⁹⁰/ᵇ

Taking the log of both side

log[1/(0.0156)] = log(2⁹⁰/ᵇ)

log[1/(0.0156)] = 90/b(log2)

90/b = log[1/(0.0156)]/log2

90/b = 6.0023

b = 90/6.0023

b = 14.99 hours

b = 14.99 hours.

Hence the half-life of Sodium-24 is 14.99 hours

7 0

3 years ago

At the rate shown in the table, how many weeks did it take to sell 700 books? [Type your answer as a number.]

WINSTONCH [101]

Answer:

to sell 7000 it took 10 weeks

it took 3 weeks to sell 210 books

Step-by-step explanation:

3 0

2 years ago

Read 2 more answers

Fine the sum of 2/9+3/5​

Fine the sum of 2/9+3/5