Help
well you have two angles A and C, how would you find the missing angle B?
law of sines
remember, when you have two angles in a triangle, 180 - angle - other angle = will give you the missing angle
oh okay so 180-42-83=55
yup then for part II) you can use a/sinA = b/sinB to find a
a/sinA = b/sinB 175/42=b/83
2075/6
check again, angle B is not 83 degrees
also you need to include sin in the denominators
a/sinA = b/sinB 175/sin42=b/sin55 b=214.24
175 is side b not a we are solving for side a
a/sin(42) = 175/sin(55)
142.95
A+
oh right I forgot it's asking for side c too you can use law of cosines i guess
c^2 = a^2 + b^2 - 2ab * cos(C) you have everything except c, solve for c
should be -2ab not -2ac
c²=a²+b²-2abCos(C) c^2=142.95^2+175^2-2*142.95*175 (Cos(83) c^2=44962.3 c=212.0
A+ well done
well same logic as the previous problem, we are given two angles, how would we find the missing angle A?
part I -- 180-35-45=20
for part 2 are we solving for angle B?
I mean b
check your math again 180 - 45 - 35 = 100 not 20 for part II) yes, use law of sines to find side b
17/sin(100) = b/sin(45)
b=12.21
have to be very careful with your a, b, and c labels|dw:1527178374588:dw|
a is always across angle A b is always across angle B c is always across angle C
so looking at your diagram a/sin(A) = c/sin(C) = ?
a/sin(A) = c/sin(C) a/sin(100)=17/sin(35) a=29.2
good then for part III) use law of cosines to find b
b²=a²+c²-2acCos(B) b^2=29.2^2+17^2-2*29.2*17 (cos35) b^2-328.39 b=18.12
A+ well done
part I 180-130-30=20
good, then use law of sines for part II to find d
d/sin130=35/sin30
ugh this :/
almost d/sin(130) = 35/sin(20) not 30degrees
d=78.39
good then for part III you can find the missing side (from suzie to the boat) using law of cosines
there is only two parts to this question :/
oh ok cool
don't forget your units (Feet)
b²=a²+c²-2acCos(B) 21^2=22^2+16^2-2*22*16 (cos B)
The calc for some reason is not giving me an answer is 299 roght?
21^2=22^2+16^2-2*22*16*x try solving for x, then take the arccos of the result
64.87
good then for part II, law of sines to find C
b/sin(B)=c/sin(C) 21/sin(64.87)=16/Sin(C) C=84.22 degrees
hm, try that again 21/sin(64.87)=16/x try solving for x then take the arcsin of the result
42.84
good, then for part III we have angle B and angle C so angle A = 180 - B - C
180 - 42.84 - 64.87 = ?
72.29 sorry I was afk
good
b²=a²+c²-2acCos(B) 18^2=
ugh im confused
we want to find side a we have angle A, side b, and side c a^2 = b^2 + c^2 - 2(b)(c)cos(A)
a^2 = b^2 + c^2 - 2(b)(c)cos(A) a^2=18^2+20^2-2*18*20 (Cos 95)
check your notation again a^2=18^2+20^2-2*18*20*cos(95)
click the approximate form button
28.049
good so 28.049 feet for part II: plug in d = r*t where d is the distance, r is the speed of car A, t is time, solve for time
28.049=30*t t=0.93
oh whoops that's car B so that would be part III for part II use the distance of car A (18 miles) and the speed from car A (30 mph)
18=30*t
like that
good
t=3/5
for part II
good for part III use the distance 28.049 feet and speed 45 mph
28.049=45*t t=0.62
would it be seconds?
travelling 28 miles in 0.62 would be quite a feat the speed is given in mph so hours not seconds
so 0.62 hours
good so for part IV car B is greater by (0.62-0.60) hours
0.02
good
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