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2 years ago

I need to know the answer

Mathematics

1 answer:

Elena L [17]2 years ago

4 0

9514 1404 393

Answer:

D. 105 ft²

Step-by-step explanation:

The total surface area is the sum of the base area and the triangular face areas.

Area of base:

A = s²

A = (7 ft)² = 49 ft²

Area of 4 triangles:

A = 4(1/2)bh

A = 2(7 ft)(4 ft) = 56 ft²

Total surface area:

base area + triangle area = 49 ft² +56 ft² = 105 ft²

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option 1 drop down are: even-odd identity, quotient identity, Pythagorean identity, double-number identity.option 2 drop down ar

motikmotik

Answer:

The equation is given below as

$\frac{\cos2x}{\cos x}=\cos x-\sin x\tan x$

Step 1:

We will work on the left-hand side, we will have

$\begin{gathered} \cos x-\sin x\tan x \\ \text{recall that,} \\ Quoitent\text{ identity is} \\ \tan x=\frac{\sin x}{\cos x} \end{gathered}$

By substituting the identity above, we will have

$\begin{gathered} \cos x-\sin x\tan x=\cos x-\frac{\sin x.\sin x}{\cos x}=\cos x-\frac{\sin^2x}{\cos x} \\ \end{gathered}$

Here, we will make use of the quotient identity

Step 2:

By writings an expression, we will have

$\begin{gathered} \cos x-\sin x\tan x=\cos x-\frac{\sin x.\sin x}{\cos x} \\ \cos x-\sin x\tan x=\frac{\cos^2x-\sin^2x}{\cos x} \end{gathered}$

Here, we will use the definition of subtraction

$\cos x-\frac{\sin^2x}{\cos x}$

Step 3:

We will apply the double number identity given below

$\begin{gathered} \cos 2\theta=\cos (\theta+\theta)=\cos ^2\theta-\sin ^2\theta \\ \cos 2x=cos(x+x)=\cos ^2x-\sin ^2x \end{gathered}$

By applying this, we will have

$\frac{\cos^2x-\sin^2x}{\cos x}=\frac{\cos2x}{\cos x}$

Here, we will use the double number identity

$\frac{\cos^2x-\sin^2x}{\cos x}$

5 0

1 year ago

A number divided by three less two is at most two

Marina CMI [18]

x ≤ 12

Solution:

Let us take the number be x.

A number : x

A number divided by three : $$\frac{x}{3}$

A number divided by three less two : $$\frac{x}{3}-2$

A number divided by three less two is at most two : $$\frac{x}{3}-2\leq 2$

Now, simplify the inequality,

$$\Rightarrow\frac{x}{3}-2\leq 2$

Add 2 on both sides of the inequality,

$$\Rightarrow\frac{x}{3}-2+2\leq 2+2$

$$\Rightarrow\frac{x}{3}\leq 4$

Multiply by 3 on both sides of the equation,

$$\Rightarrow\frac{x}{3}\times3\leq 4\times3$

$$\Rightarrow x\leq 12$

Hence x ≤ 12.

5 0

3 years ago

Find the discriminant<br> 9x^2+14x+13=8x^2

tiny-mole [99]

Answer:

The discrimant of this equation is 144.

Step-by-step explanation:

First you have to move all the variables to one side to make the equation/expression into 0 by substracting 8x² to both sides :

9x² + 14x + 13 = 8x²

9x² + 14x + 13 - 8x² = 8x² - 8x²

x² + 14x + 13 = 0

It is given that the formula of discriminant is, D = b² - 4ac where a&b&c represent the number of the equation, ax²+bx+c = 0 :

x² + 14x + 13 = 0

D = b² - 4ac

= 14² - 4(1)(13)

= 196 - 52

= 144

8 0

3 years ago

Ahmad is choosing a password to access his teacher’s web page. He must choose a capital letter and three nonrepeating digits fro

algol [13]

Answer:

0a23,02A3

Step-by-step explanation:

I think that this is the right answer Im sorry if it is wrong

7 0

2 years ago

Read 2 more answers

How would I find angle B for this bridge? What formula would I use?

astraxan [27]

The bridge attached is drawn according to given dimensions, and it doesn't look right. Please double check the given dimensions.

Calculations:
Horizontal part of bottom chord below the 70 degree triangle
= 15.1*cos(70) = 5.16 (which is a major prt of the 6.3 units.
Height of vertical pieces DF and EH
= 15.1*sin(70) = 14.19
Note that structurally, DF and EH do not help in reducing stress on the bridge, since they are perpendicular to the bottom chord.

Therefore
angle B = atan(14.19/(6.3-5.16))=85.41 degrees

I believe the whole geometry does not look right, esthetically, and structurally, since the compression members are much longer than the tension members in the middle. (The vertical members carry no force.)
If you can review the input data, or post a new question, I will be glad to help.

4 0

2 years ago

Read 2 more answers