1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
yaroslaw [1]
3 years ago
8

Given that Triangle ABC such thata=8cm, b=7cm and c=9cmtem and c= 9cm find Cos B​

Mathematics
1 answer:
charle [14.2K]3 years ago
4 0

Answer:

We use cosine rule also called cosine law which states

c^2=a^2+b^2-2abcosC

given

a=8cm, b=7cm, c=9cm cos C?

9^2=8^+7^2-2*8*7 cos C

expand

81=64+49-112 cos C

like terms together

81-113=-112 cos C

-32=-112cos C

multiply both sides by -1

32=112cos C

divide both sides by 112

32/112=cos C

cosC=0.2857

find cos inverse of 0.2857

angle C= 73.40

You might be interested in
Five cats ate 1/4 cup of food how much food did five cats eat
Maslowich
If it was EACH cat they had 1.25 cups otherwise they all shared the 1/4 cup offered.

7 0
2 years ago
25ft+25ft+20ft+20ft+2.5ft+2.5ft+8ft+13ft
Anna71 [15]

we are given

25ft+25ft+20ft+20ft+2.5ft+2.5ft+8ft+13ft

Since, every value is in ft

so, we can take out ft

=(25+25+20+20+2.5+2.5+8+13)ft

now, we can add them

and we get

=116ft............Answer

7 0
3 years ago
Your work or words should justify your answer (explain how you know). As a math teacher, Josie frequently makes photocopies of f
Doss [256]

Answer:

Yes, because by dividing x by his equivalent y, you find a constant of proportionality being 10.

x / y = 10

Step-by-step explanation:

20 / 2 = 10

50 / 5 =10

60 / 6 = 10

70 / 7 = 10

7 0
2 years ago
A community college has a math placement exam that has a mean of 65 and a standard deviation of 8.2. If a student takes the exam
Marat540 [252]

Answer:

The score that cuts off the bottom 2.5% is 48.93.

Step-by-step explanation:

When the distribution is normal, we use the z-score formula.

In a set with mean \mu and standard deviation \sigma, the zscore of a measure X is given by:

Z = \frac{X - \mu}{\sigma}

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this question, we have that:

\mu = 65, \sigma = 8.2

What is the score that cuts off the bottom 2.5%

This is X when Z has a pvalue of 0.025, so X when Z = -1.96.

Z = \frac{X - \mu}{\sigma}

-1.96 = \frac{X - 65}{8.2}

X - 65 = -1.96*8.2

X = 48.93

The score that cuts off the bottom 2.5% is 48.93.

8 0
3 years ago
Read 2 more answers
Can anyone help me with this math problem plss?
gulaghasi [49]

Answer:

14/24 ( simplified = 7/12)

Step-by-step explanation:

to find this we multiply the fractions 2/3 and 7/8

7/8 x 2/3 = 14/24

So Shannon ate 14/24 lb

You can simplify to = 7/12

3 0
2 years ago
Other questions:
  • What is the equation in point−slope form of the line passing through (1, 2) and (2, 5)? (5 points)
    5·1 answer
  • I need help to figure this out?<br>can someone help me?
    12·1 answer
  • On this chapter quiz for this course you can study for up to four hours If you don't study at all you will get a 70. One hour wo
    6·1 answer
  • Perform the indicated operations on the following polynomials.
    15·1 answer
  • If a geometric sequence has a2 = 495 and a6 = 311, approximate the value of the common ratio ???? to four decimal
    6·1 answer
  • Dilate the given points distance from the origin (x,y) (0.8x, 0.8y) . The point (-10,-20) becomes &amp; point (15,25) become
    13·1 answer
  • What the sequence of 10,12,15,19
    11·1 answer
  • The prices for different prices at a grocery store are shown in the table below which of the following spices has the least pric
    7·1 answer
  • SOMEONE PLEASE HELP!!!!
    6·2 answers
  • Solve the system by substitution. <br><br><br><br>9y - 6 = x <br>2x - 8y = 18​
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!