Member: Rom

Quote:
At a certain point in a large, level park, the angle of elevation to the top of an office building is 30 degrees. If you move 400ft closer, the angle of elevation is 45 degrees. To the nearest 10 ft, how tall is the building?

tan(30) = H/D = sqrt(3)/3
H = D * sqrt(3)/3

tan(45) = H/(D-400) = 1
D-400 = H

D-400 = D * sqrt(3)/3
D(1 - sqrt(3)/3) = 400

D = 400/(1 - sqrt(3)/3)) = 946.41
H = D - 400 = 546.41

RomMar 5, 2014

+6251

Quote:
help! whats 14-8x=104-43x x=? HELP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

ARE YA OK???????

14 - 8x = 104 - 43x

35x = 90

x = 90/35 = 18/7

14-8x=104-43x

RomMar 5, 2014

+6251

Quote:
4 sin x = 1 [0,2pi)

4 sin(x) = 1

sin(x) = 1/4

there are going to be 2 values of x for which this is true in [0, 2pi]

x=0.252680255142 radians and x=(pi -0.252680255142) = 2.8889123984477932 radians

RomMar 4, 2014

+6251

it points straight down in the -y direction so it's angle is either

270 degrees, or -90 degrees, or

3pi/2 radians or -pi/2 radians

RomMar 4, 2014

+6251

Quote:

23q+3b=-9
21q-4b=3

probably the easiest way to go about this is using row reduction.

add 4 times the first equation to 3 times the second to get rid of the b variable

4(23q+3b=-9) +
3(21q-4b=3) =

92q+12b=-36 +
63q-12b=9
=
155q=-27

q = -27/155

from the second equation

21(-27/155)-4b=3

-567/155 - 4b = 3

4b = -567/155 - 3

b= (-567/155 - 3)/4 = -258/155

so (q,b) = (-27/155, -258/155)

RomMar 3, 2014

+6251

well I'm glad I kept my responses brief.

I have to admit I had didn't recognize either of those names.

(next time I'll do my Foster Brooks act!)

RomMar 1, 2014

+6251

it would help greatly if you were able to tell us what the probability distribution of X is.

RomMar 1, 2014

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