If cos 0=sin b then which of the following must be true?

-2x times -3x times x

topjm [15]

6x^3 a negative times a negative cancels out making it positive

5 0

3 years ago

David performed the following mathematical operation .

sweet [91]

Answer:

C: x = 1/2

Step-by-step explanation:

Set the divisor, 2x - 1, equal to zero and solve for x: 2x = 1, so x = 1/2. Statement C is true.

3 0

3 years ago

Read 2 more answers

A student was asked to identify the following numbers as rational or irrational. Determine if the student has made any mistakes.

ioda

Answer:

Yes they are wrong, rational & irrational ones down below.

Step-by-step explanation:

So, lets start this by asking, what is a rational and irrational number?

Rational numbers are literally any numbers that arent pi, e, or other symbols, as well as square roots.

Irrational numbers are exactly the opposite, being the numbers that are symbols, including square roots.

Note that the symbols listed above such as pi are values that are neverending.

Now, using what we know of rational and irrational numbers, let see which answers are rational and which are not.

So, we start off with:

-13/3

I do not see a square root.

I do not see a symbol such as pi either.

It is not a ever going number.(number that continues infinitly)

So -13/3 is a rational number.

Next we have $\sqrt{37}$

immediatly we tell it has a square root.

So $\sqrt{37}$ is a irrational number.

Next we have 0.1234

This is not a every going number.

There isnt a square root.

And it isnt a symbol.

So 0.1234 is a rational number.

Next we have $-\sqrt{100}$

Again, we can immediatly know it has a square root.

So $-\sqrt{100}$ is a irrational number.

Next we have -77

This is not every going.

It doesnt have a square root.

It doesnt have a symbol.

So -77 is a rational number.

Lastly we have $-\sqrt{12}$

Like the other ones, we can imediatly tell it has a square root.

So $-\sqrt{12}$ is a irrational number.

Bascially, to answer further questions, here is the criteria for a number being rational:

It does not have a square root.
It does not have a symbol.
It is not a infinitly going on number.

If one of these criterias are not met, then you know its a irrational number.

Hope this helps! :D

6 0

3 years ago

In a group of 60 children, there are twice as many boys as girls. How many girls are there?

yaroslaw [1]

$g-girls\\2g-boys\\\\g+2g=60\\3g=60\ \ \ \ |divide\ both\ sides\ by\ 3\\\boxed{g=20}\leftarrow answer$

3 0

4 years ago

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A water trough is 7 feet long, and its cross section is an equilateral triangle with sides 4 feet long. Water is pumped into the

Tju [1.3M]

Answer:

a. An equilateral triangle main characteristic is that all the sides lenght are the same (s). To find the height (h), we could divide the triangle (as seen in the picture) and apply Pytagorean theorem.

$(\frac{s}{2}) ^{2} +h^{2}=s^{2}$

Clearing the expression, we obtain: $h= \frac{\sqrt{3}}{2}s$

b. Knowing the rate at which the volume is changing 4 $ft^{3}$ , we can find the relation between the change in the volume and the height.

$V=A*h$

As we want to express the volume in terms of the height, we have to find the area in terms of height

$A=\frac{base*height}{2}$

Base=s= $\frac{2h}{\sqrt{3}}$

Therefore, $A=\frac{\frac{2h}{\sqrt{3}} *h}{2} =\frac{h^{2} }{\sqrt{3}}$

$V=7 ft*\frac{h^{2}}{\sqrt{3}}$

Therefore the change in the volume with the height, will be the derivate of this expression

$\frac{dV}{dt} =2*7*\frac{h}{\sqrt{3}} (\frac{dh}{dt} )$

Knowing dV/dt=4 cubic feet per second, and h=1/2 foot, we can know dh/dt

$\frac{dh}{dt}=\frac{\frac{dV}{dt}*\sqrt{3}}{7*2*h} =\frac{4*\sqrt{3} }{14*\frac{1}{2} }=0.98 ft/sec$

Step-by-step explanation:

7 0

4 years ago