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3 years ago

How should we prove this ? Boc=90-1/2angle bac

Mathematics

1 answer:

Hatshy [7]3 years ago

8 0

We have m(<CBO) = (1/2) · m(<CBE) = (1/2) · ( x + z );

In the same way, m(<BCO) = (1/2) ·( x + y);

m(<BOC) = 180 - [(1/2) · ( x + z ) + (1/2) ·( x + y)] = 180 - (1/2)· ( x + x + y + z );

But, x + y + z = 180;

Then, m(<BOC) = 180 - (1/2)·( x + 180 );

Finally, m(<BOC) = 90 - (1/2)·x;

So, m(<BOC) = 90 - (1/2)·m(<BAC).

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Heston found the opposite of a number to be negative 4.2. What is the number?

Daniel [21]

Um 4.2 maybe since -4.2 and 4.2 or on the opposite scale

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2 years ago

The range of the following relation R{(3,-2), (1, 2), (-1, -4), (-1, 2)} is O{-1.1,3) -1,-1,1.3 01-4, 2, 2, 2] {-4, -2, 2

maw [93]

Answer:

The range is -2,2,-4

Step-by-step explanation:

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3 years ago

What is 1.8 added 8 times? (IF YOU CAN PLS DO IT IN EXPLANATION) and this is about decimals and pls do it in grade five type, bc

Salsk061 [2.6K]

Answer:

14.4

Step-by-step explanation:

1.8 added 8 times = 1.8 * 8

1.8 * 8

use distributive property

1.8 = 1 + 0.8

1.8 * 8 = (1+0.8) * 8

= 1*8 + 0.8*8

anything multiplied by 1 equals itself

1*8 + 0.8*8 = 8 + 0.8 * 8

0.8 = 8/10

0.8 * 8 = (8/10) * 8

= 64/10

= 6.4

8 + 0.8 * 8 = 8 + 6.4 = 14.4 as our answer

8 0

2 years ago

Y is six more than x divided by three turn it into an expression (y=mx+b format)

Snowcat [4.5K]

We always start from right side in order of operation in any equation

we can set up equation as

step-1:

x divided by three

we can write as

$=\frac{x}{3}$

step-2:

six more than x divided by three

so, we get

$=\frac{x}{3}+6$

step-3:

y is six more than x divided by three

so, we get

$y=\frac{x}{3}+6$

and this is in y=mx+b form

so, we have

$y=\frac{x}{3}+6$ ...............Answer

4 0

3 years ago

An electronics company produces transistors, resistors, and computer chips. Each transistor requires 3 units of copper, 1 unit

padilas [110]

Answer:

An electronics company can be produce 350 transistors and 340 computer chips, they can´t produce resistors.

Step-by-step explanation:

1. We will name the variables for transistors, resistors and the computer chips.

a = Transistors

b= Resistors

c = Computer chips

2. We propose three linear equations, one for the copper, one for the zinc and one for the glass.

$\left \{ {{3a+3b+2c=1730} \atop {a+2b+c=690}}\atop {2a+b+2c=1380}} \right.$

3. We write the matrix form as Ax=d

$A=\left(\begin{array}{ccc}3&3&2\\1&2&1\\2&1&2\end{array}\right)$

$x=\left(\begin{array}{ccc}a\\b\\c\end{array}\right)$

$A=\left(\begin{array}{ccc}1730\\690\\1380\end{array}\right)$

With this formula the solution of x is $x=\frac{d}{A}$ or $x=A^{-1}d$

4. We will find the inverse matrix $A^{-1}$ using the formula:

$A^{-1} = \frac{1}{detA} (C_{A})^{T}$

a. det A

$det A=\left[\begin{array}{ccc}3&3&2\\1&2&1\\2&1&2\end{array}\right] =3*(4-1)-3*(2-2)+2*(1-4)=9-0-6=3$

b. $(C_{A})^{T}$

$C_{A}=\left(\begin{array}{ccc}4-1&.(2-2)&1-4\\-(6-2)&6-4&-(3-6)\\3-4&-(3-2)&6-3\end{array}\right)$

$C_{A}=\left(\begin{array}{ccc}3&.0&-3\\-4&2&3\\-1&-1&3\end{array}\right)$

$(C_{A}) ^T=\left(\begin{array}{ccc}3&0&-3\\-4&2&3\\-1&-1&3\end{array}\right)^T$

$(C_{A}) ^T=\left(\begin{array}{ccc}3&-4&-1\\0&2&-1\\-3&3&3\end{array}\right)$

c. $A^{-1}$

$A^{-1}=\frac{1}{3} \left(\begin{array}{ccc}3&-4&-1\\0&2&-1\\-3&3&3\end{array}\right)$

5. As $x=\frac{d}{A}$ or $x=A^{-1}d$ , the solution of x is:

$x=\frac{1}{3}\left(\begin{array}{ccc}3&-4&-1\\0&2&-1\\-3&3&3\end{array}\right)\left(\begin{array}{ccc}1730\\690\\1380\end{array}\right)$

$x=\frac{1}{3}\left(\begin{array}{ccc}(3*1730)+(-4*690)+(-1*1380)\\(0*1730)+(2*690)+(-1*1380)\\(-3*1730)+(3*690)+(3*1380)\end{array}\right)$

$x=\frac{1}{3}\left(\begin{array}{ccc}1050\\0\\1020)\end{array}\right)$

$X=\left[\begin{array}{ccc}350\\0\\340\end{array}\right]$

Therefore:

a= 350 Transistors

b=0 Resistors

c=340 Computer chips

4 0

3 years ago