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A 12-meter ladder leans against a building forming a 30° angle with the building.

KatRina [158]

Answer:

will show you two (2) ways to solve this problem.

A diagram is needed to see what is going on....

Without loss of generality (WLOG)

The wall is on the right. The ladder leans against the wall

with a POSITIVE slope, from SW to NE (quadrant 3 to quadrant 1).

The measure from the bottom of the ladder to the wall is 6.

Option 1:

The ladder, ground and wall form a right triangle.

The hypotenuse (ladder) is 14 feet.

The bottom of the ladder is 6 feet from the wall,

so the base of this right triangle is 6 feet.

The top of the ladder to the ground represents

the missing leg of the right triangle.

The pythagorean theorem applies, which says

6^2 + h^2 = 14^2 where h is the height

of the top of the ladder to the ground

36 + h^2 = 196

h^2 = 196 - 36

h^2 = 160

h = sqrt(160)

= sqrt(16 * 10)

= sqrt(16)* sqrt(10)

= 4*sqrt(10) <--- exact answer

= 4 * 3.16227766016838....

= 12.64911....

12.65 <--- rounded to 2 digits as directed

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

Option #2: using trig

With respect to the angle formed by the bottom of the

ladder with the ground

cos T = 6/14 = 3/7

T = inverse-cosine(3/7) = 64.623006647 degrees

sin(64.623006647) = h/14

h = 14*sin(64.62300647) = 12.6491106 <--- same answer

hope this helps

Step-by-step explanation:

5 0

3 years ago

At a pet store the ratio of cats to dogs sold was 10:1. If there were 60 cast that were sold, how many dogs were sold?

AnnZ [28]

Ratio for this mean for every 10 cats sold there was one dog

60/10 = ?

6 dogs

ratio = 60:6

3 0

3 years ago

Y = 2/3 x -3 y = -3/2 x +2 what statement about the lines are true

Hoochie [10]

Answer:

The product of the slopes of lines is -1.

i.e. m₁ × m₂ = -1

Thus, the lines are perpendicular.

Step-by-step explanation:

The slope-intercept form of the line equation

$y = mx+b$

where

m is the slope

b is the y-intercept

Given the lines

y = 2/3 x -3 --- Line 1

y = -3/2x +2 --- Line 2

<u>The slope of line 1</u>

y = 2/3 x -3 --- Line 1

By comparing with the slope-intercept form of the line equation

The slope of line 1 is: m₁ = 2/3

<u>The slope of line 2</u>

y = -3/2x +2 --- Line 2

By comparing with the slope-intercept y = mx+b form of the line equation

The slope of line 2 is: m₂ = -3/2

We know that when two lines are perpendicular, the product of their slopes is -1.

Let us check the product of two slopes m₁ and m₂

m₁ × m₂ = (2/3)(-3/2 )

m₁ × m₂ = -1

Thus, the product of the slopes of lines is -1.

i.e. m₁ × m₂ = -1

Thus, the lines are perpendicular.

7 0

3 years ago

Mr. Smith traveled to a city 300 miles from his home to attend a meeting. Due to car trouble, his average speed returning was 6

Kryger [21]

Answer: The speed at which he traveled to the city is 69.8 mph

Step-by-step explanation:

Let x represent the speed at which he traveled to the city.

Mr. Smith traveled to a city 300 miles from his home to attend a meeting.

Time = distance/speed

Time taken to travel to the city is

300/x

Due to car trouble, his average speed on returning was 6 mph less than his speed going. This means that the speed at which he returned is (x - 6) mph. Time taken to return from the city is

300/(x - 6)

If the total time for the round trip was 9 hours, it means that

300/x + 300/(x - 6) = 9

Cross multiplying by x(x - 6), it becomes

300(x - 6) + 300x = 9x(x - 6)

300x - 1800 + 300x = 9x² - 54x

9x² - 54x - 300x - 300x - 1800 = 0

9x² - 654x -1800 = 0

Applying the general quadratic equation,

x = [- b ± √(b² - 4ac)]/2a

From the equation given,

a = 9

b = - 654

c = 1800

Therefore,

x = [- - 654 ± √(- 654² - 4 × 9 × 1800)]/2 × 9

x = [654 ± √(427716 - 64800)]/18

x = [654 ± √362916.4]/18

x = (654 + 602.4)/2 or x = (654 - 602.4)/18

x = 1256.4/18 or x = 51.6/18

x = 69.8mph or x = 2.9 mph

The speed at which he traveled to the city is 69.8 mph

By checking,

Time spent travelling to the city = 300/69.8 = 4.3 hours

Time spent returning =

300/(69.8 - 6) = 4.7 hours

4.3 + 4.7 = 9 hours

3 0

3 years ago

12x-y when x= 1/3, y=-2

Basile [38]

Answer:

Step-by-step explanation:

12 x 1/3-2

4 0

3 years ago

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