Question

i need some help

Answer 1

@Vocaloid

Answer 2

yikes, I'm not quite sure about this one

coordinate plane? I can't really find much on the internet

Answer 3

what about this?

Answer 4

alright, this is kind of hard to explain because it requires you to use a bit of imagination/visualization

but there need to be four long sides, and two small square "caps" that can fold on either side of the shape

with that being said what might be the best choice?

Answer 5

top right one?

Answer 6

good

Answer 7

good

Answer 8

hm, not quite

first find the missing angle, using the fact that all angles in a triangle sum up to 180

then use law of sines to find the missing side

Answer 9

81?

Answer 10

good, then use law of sines to find the missing side

Answer 11

9.4?

Answer 12

got close to that

Answer 13

8/sin(81) = x/sin(44)

x = ?

Answer 14

-12.70

Answer 15

make sure you're using degrees not radians

Answer 16

8.009?

Answer 17

8/sin(81) = x/sin(44)

cross multiply to get

8sin(44) = x*sin(81)

solve for x

make sure your calc is in degrees mode

Answer 18

5.6

Answer 19

good so 5.6 = your sol'n

Answer 20

good

Answer 21

check your calculations again



use law of cosines. let the missing side x be C

Answer 22

ok

Answer 23

let's look at your diagram

c = the missing side x

the angle is 128 degrees
a and b are the other two sides 420 and 330

therefore

x^2 = (420)^2 + (330)^2 + 2(330)(420)cos(128)

solve for x.

Answer 24

338.5

Answer 25

x^2 = (420)^2 + (330)^2 + 2(330)(420)cos(128)


therefore you just need to plug

(420)^2 + (330)^2 + 2(330)(420)cos(128)


into a calculator

then take the square root of the result

make sure your calculator is in degrees mode

Answer 26

750

Answer 27

start with this 2(330)(420)cos(128)

what do you get?

Answer 28

45181.0

Answer 29

let's break it down step by step

cos(128) = ?

Answer 30

-0.42

Answer 31

what sort of calculator are you using?

Answer 32

a scientific calculator

Answer 33

the one that comes pre-installed in windows 8.

Answer 34

is it actually -0.69

Answer 35

yup, it should be around -.69

for calculators like this you need to clear the calculator, press 128, then press the cos button (it's backwards from how a real one usually works)

Answer 36

562500

Answer 37

*should be a minus sign in between the 330^2 and the 2(330)(420)cos(128)

Answer 38

but anyway, remember your order of operations

remember order of operations

1. calculate (420)^2
2. calculate (330)^2
3. calculate 2(330)(420)cos(128)

then add the first 2 quantities, then subtract the last quantity

Answer 39

8100

Answer 40

1. calculate (420)^2 = 176400
2. calculate (330)^2 = 108900
3. calculate 2(330)(420)cos(128) = -170661.361

now calculate (420)^2 + (330)^2 - 2(330)(420)cos(128)

Answer 41

477370.722

Answer 42

(420)^2 + (330)^2 - 2(330)(420)cos(128)

= 176400 + 108900 - (-170661.361) = ?

Answer 43

455961

Answer 44

good now take the square root

Answer 45

675

Answer 46

jfc..

Answer 47

good so 675 = your sol'n

Answer 48

not quite, check your calculations again

use law of cosines where

c^2 = a^2 + b^2 - 2*a*b*cos(C)

c is the missing side; a and b are the given sides; C is the angle

solve for c

Answer 49

130585

Answer 50

c^2 = a^2 + b^2 - 2*a*b*cos(C)

plugging in the values we get

c^2 = 252^2 + 229^2 - 2(229)(252)*cos(94)

evaluate what 252^2 + 229^2 - 2(229)(252)*cos(94) and take the square root

Answer 51

can't sove it, lemme try it manually

Answer 52

4053

Answer 53

252^2 = 63504

229^2 = 52441

2(229)(252)*cos(94) = -8051.01

plugging these into the formula gives us

63504 + 52441 - (-8051.01) = ?

Answer 54

123996.01

Answer 55

good then take the square root to get your sol'n

Answer 56

not quite

using law of sines

72/sin(46) = 90/sin(x)

solve for x

Answer 57

1.11

Answer 58

that's in radians, convert that to degrees

Answer 59

2.02?

Answer 60

to convert from radians to degrees, multiply by (180/pi)

1.11 * (180/pi)
= ?

Answer 61

63.5

Answer 62

good so 64 = your sol'n

Answer 63

good

Answer 64

you don't know any angles so you can't use law of sines

Answer 65

good

Answer 66

not quite

remember

sin(angle)/side across from the angle

Answer 67

so the top right one then?

Answer 68

good

Answer 69

good

Answer 70

good

Answer 71

good

Answer 72

good

Answer 73

good

Answer 74

hm. not quite.

angle = arctan(y/x)

so you need to calculate the angle of the plane before the wind (160,-120)
and the angle after the wind is applied (160 + 40, -120 + 40)

Answer 75

120

Answer 76

and 40

Answer 77

let's take it one step at a time

angle = arctan(y/x)
for the first plane (160,-120), what is arctan(y/x) = ?

Answer 78

1.107

Answer 79

arctan(-120/160) = ?

make sure you are using arctan not tan

Answer 80

-0.64

Answer 81

good but let's use degrees instead

-0.64 in degrees is -36.87 degrees

now apply the same logic to find the angle of (160 + 40, -120 + 40)

Answer 82

1,56246319

Answer 83

let's try that again

(160 + 40, -120 + 40) = (200,-80)

arctan(-80/200) in degrees = ?

Answer 84

-0.0066410891

Answer 85

arctan(-80/200 = -21.8 degrees

therefore the difference = -36.87 - (-21.8) = -15.07

so there's a 15 degree difference = your sol'n

Answer 86

good

Answer 87

hm not quite

if you draw a right triangle between the lake and pool you get a right triangle w/ legs 5 and 1

so what would be the hypotenuse if the legs are 5 and 1?

Answer 88

7?

Answer 89

wait, 5

Answer 90

hypotenuse = sqrt(leg^2 + leg^2)

Answer 91

5.09

Answer 92

the answers in radical form so sqrt(5^1 +1^1) = sqrt(26) = your sol'n

Answer 93

speed is a scalar so it's always positive

so 28.3 not -28.3

Answer 94

the x-coordinate comes first

make sure to also consider the direction, too

Answer 95

for example, from A to B it goes 1 unit to the left so we have -1 as the x-coordinate

then we go 4 units up as the y-coordinate

giving us (-1,4) as the sol'n