![ellie4678](/avatars/21691.jpg)
ellie4678
16.12.2020 •
Mathematics
A. NOT CONGRUENT
b. AAS
c. SSS
d. ASA
e. SAS
Solved
Show answers
More tips
- F Family and Home Do You Really Need a Playpen for Your Child?...
- F Food and Cooking Do Aphrodisiacs Really Work? Separating Fact from Fiction...
- C Computers and Internet Log-in: what is it and why do you need it?...
- S Style and Beauty Secrets of Tying a Pareo: 5 Ways...
- F Food and Cooking Everything You Need to Know About Pasta...
- C Computers and Internet How to Choose a Monitor?...
- H Horoscopes, Magic, Divination Where Did Tarot Cards Come From?...
- S Style and Beauty How to Make Your Lips Fuller? Ideas and Tips for Beautiful Lips...
Answers on questions: Mathematics
- M Mathematics The number of miles a car travels varies directly with the number of gallons of gas in its tank of a car with 20 gallons of gas can drive 560 miles which equation represents the...
- M Mathematics Solve for x. (Will be marked the brainliest for sure)...
- M Mathematics LOGRARITHIM PLZ HELP WILL MARK BRAINLIEST...
- M Mathematics Entre la media y la mediana que valor consideras que es más representativo plz...
- M Mathematics Tell whether the angles are adjacent or vertical. Then find the value of x....
- M Mathematics SOMEONE PLZ HELPP ME The last options are Y=log10x...
- M Mathematics How would the graph of f(x) = -3(x+2)^2 -5 be affected if the function was changed to f(x) = 1/2(x-2)^2 -5?...
- M Mathematics Graph the line with the equation y= 4/5 x+2....
- M Mathematics Can someone help me with this please...
- M Mathematics 22/25 Which graph has an even degree with a positive leading coefficient? ISO f(x)=-4x+168431x2-491-30 Positive Leating Coeficient Even Degree f(x)x - 141-4 200+ 125 10+ 100 100+...
Ответ:
Correct cos(α - β) = 140/221
Step-by-step explanation:
cosα = ±√(1 - sin²α) => cosα = ±√(1 - (-5/13)²) = ±√(1 - (25/169)
cosα = ±√(169 -25)/169 = ± √144/169
cosα = ± 12/13 since it is given that α (alpha) ends in the third quadrant
we choose cosα = - 12/13
we know that is tanβ = sinβ/cosβ = - 8/15 or sinβ : cosβ = 8 : 15 =>
sinβ = 8k and cosβ = 15k where k is the coefficient of proportionality
we know the basic trigonometric equality
sin²β + cos²β = 1 when we replace the coefficients we get
(8k)² + (15k)² = 1 => 64k² + 225k² = 1 => 289k² = 1 => k² = 1/289 =>
k = 1/17 now we get sinβ and cosβ
since it is given that β (beta) ends in the second quadrant
sinβ = 8/17 and cosβ = - 15/17
As we know it is:
cos(α - β) = cosα cosβ + sinα sinβ = - 12/13 · (- 15/17) + (- 5/13) · 8/17 =>
cos(α - β) = 180/221 - 40/221 = 140/221
cos(α - β) = 140/221
God is with you!!!