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2 years ago

13

An engineer stands 30 ft. from a building and notes a 55 degree angle of elevation to the top of the building. How high is the b

uilding? Round your answer to 1 decimal place.

1 answer:

alexdok [17]2 years ago

8 0

<h3>Answer: 42.8 feet</h3>

Work Shown:

h = height of the building

h is opposite the reference angle (55)

the adjacent side is 30 feet

tan(angle) = opposite/adjacent

tan(55) = h/30

h = 30*tan(55)

h = 42.84444 which is approximate

h = 42.8 feet

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Need help will give 5 stars.

olga_2 [115]

Answer:

t=0.64

Step-by-step explanation:

h = -16t^2 +4t +4

We want h =0 since it is hitting the ground

0 = -16t^2 +4t +4

Using the quadratic formula

a = -16 b = 4 c=4

-b ± sqrt( b^2 -4ac)

----------------------------

2a

-4 ± sqrt( 4^2 -4(-16)4)

----------------------------

2(-16)

-4 ± sqrt( 16+ 256)

----------------------------

-32

-4 ± sqrt( 272)

----------------------------

-32

-4 ± sqrt( 16*17)

----------------------------

-32

-4 ± sqrt( 16) sqrt(17)

----------------------------

-32

-4 ± 4 sqrt(17)

----------------------------

-32

Divide by -4

1 ± sqrt(17)

----------------------------

8

To the nearest hundredth

t=-0.39

t=0.64

Since time cannot be negative

t=0.64

7 0

3 years ago

Read 2 more answers

Use slope formula to find the missing coordinate.<br><br> (r, 1) and (5, -7) Slope = 8/3

Lena [83]

Answer:

r=8

Step-by-step explanation:

The formula for slope is

m = (y2-y1)/ (x2-x1)

Substitute in what we know.

8/3 = (-7-1)/(5-r)

Simplify

8/3 = -8/(5-r)

We can use cross products to help us solve.

8 * (5-r) = 3 * (-8)

divide each side by 8

8/8 * (5-r) = 3 * (-8)/8

5-r = -3

Subtract 5 from each side

5-r-5 = -3-5

-r = -8

Multiply by -1

r = 8

3 0

3 years ago

<img src="https://tex.z-dn.net/?f=%20%20%5Csf%20%5Chuge%7B%20question%20%5Chookleftarrow%7D" id="TexFormula1" title=" \sf \huge

BabaBlast [244]

$\underline{\bf{Given \:equation:-}}$

$\\ \sf{:}\dashrightarrow ax^2+by+c=0$

$\sf Let\:roots\;of\:the\: equation\:be\:\alpha\:and\beta.$

$\sf We\:know,$

$\boxed{\sf sum\:of\:roots=\alpha+\beta=\dfrac{-b}{a}}$

$\boxed{\sf Product\:of\:roots=\alpha\beta=\dfrac{c}{a}}$

$\underline{\large{\bf Identities\:used:-}}$

$\boxed{\sf (a+b)^2=a^2+2ab+b^2}$

$\boxed{\sf (√a)^2=a}$

$\boxed{\sf \sqrt{a}\sqrt{b}=\sqrt{ab}}$

$\boxed{\sf \sqrt{\sqrt{a}}=a}$

$\underline{\bf Final\: Solution:-}$

$\\ \sf{:}\dashrightarrow \sqrt{\alpha}+\sqrt{\beta}$

$\bull\sf Apply\: Squares$

$\\ \sf{:}\dashrightarrow (\sqrt{\alpha}+\sqrt{\beta})^2= (\sqrt{\alpha})^2+2\sqrt{\alpha}\sqrt{\beta}+(\sqrt{\beta})^2$

$\\ \sf{:}\dashrightarrow (\sqrt{\alpha}+\sqrt{\beta})^2 \alpha+\beta+2\sqrt{\alpha\beta}$

$\bull\sf Put\:values$

$\\ \sf{:}\dashrightarrow (\sqrt{\alpha}+\sqrt{\beta})^2=\dfrac{-b}{a}+2\sqrt{\dfrac{c}{a}}$

$\\ \sf{:}\dashrightarrow \sqrt{\alpha}+\sqrt{\beta}=\sqrt{\dfrac{-b}{a}+2\sqrt{\dfrac{c}{a}}}$

$\bull\sf Simplify$

$\\ \sf{:}\dashrightarrow \underline{\boxed{\bf {\sqrt{\boldsymbol{\alpha}}+\sqrt{\boldsymbol{\beta}}=\sqrt{\dfrac{-b}{a}}+\sqrt{2}\dfrac{c}{a}}}}$

$\underline{\bf More\: simplification:-}$

$\\ \sf{:}\dashrightarrow \sqrt{\alpha}+\sqrt{\beta}=\dfrac{\sqrt{-b}}{\sqrt{a}}+\dfrac{c\sqrt{2}}{a}$

$\\ \sf{:}\dashrightarrow \sqrt{\alpha}+\sqrt{\beta}=\dfrac{\sqrt{a}\sqrt{-b}+c\sqrt{2}}{a}$

$\underline{\Large{\bf Simplified\: Answer:-}}$

$\\ \sf{:}\dashrightarrow\underline{\boxed{\bf{ \sqrt{\boldsymbol{\alpha}}+\sqrt{\boldsymbol{\beta}}=\dfrac{\sqrt{-ab}+c\sqrt{2}}{a}}}}$

5 0

2 years ago

Read 2 more answers

A bakery sells bagels at two different rates. When a customer buys fewer than 12 bagels, each one costs $1.25. When a customer b

Sav [38]

Answer:

1.25b when b < 12 , 1b & then 0.75 b when b <u>> </u>12

Step-by-step explanation:

Price for b bagels = Price x Quantity

* Less than 12 bagels bought, cost $1.25 per bagel

So, price for b bagels, when (b < 12) = 1.25b

* 12 or more than 12 bagels bought, cost $1 upto first 12 bagels & 0.75b on each additional bagel

So, price for b bagels, when (b = 12) = b

So, price for b bagels, when (b > 12) = b + 0.75b' , where b' denotes extra b beyond 12

8 0

3 years ago

True or false (picture provided)

Eddi Din [679]

False. That does not satify the equation

8 0

3 years ago

Read 2 more answers