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
prisoha [69]
3 years ago
5

3 Prove thatcos130°+cos 110+ cos10=0​

Mathematics
1 answer:
Evgesh-ka [11]3 years ago
5 0

We know, cos A + cos B = 2cos(C+D)/2 × cos(C - D)/2

So,

cos 130 + cos 110 + cos 10

cos 130 + 2cos (110+10)/2 × cos( 110-10)/2

cos 130 + 2cos 60 × cos 50

cos ( 180 - 50 ) + 2cos60 cos 50

We know, cos ( 180 - A ) = -cos A

2cos 60 cos 50 - cos 50

Also, cos 60 = 0.5

2×0.5 cos 50 - cos50

cos 50 - cos 50

0  = RHS.

Hence proved

You might be interested in
Given m||n, find the value of x
Soloha48 [4]

Answer:

(i)Here ∠HGB=∠AGE(vertically opposite angles)

∠HGB=110

∘

Now, for parallel lines l and m, with transversal t.

∠HGB+∠GHD=180

∘

(Angles on the same side of the transversal are supplementary)

110

∘

+∠GHD=180

∘

∠GHD=180

∘

−110

∘

=70

∘

(ii)For parallel lines l and m with transversal a

∠AIE=∠CJI (corresponding angles)

⇒x=100

∘

4 0
3 years ago
Hellp me for a brainly
Talja [164]

Answer:

25π or 78.5mm²

Step-by-step explanation:

A=3.14*5^{2} \\ =3.14*25\\ =78.5

5 0
3 years ago
Read 2 more answers
An oil exploration company currently has two active projects, one in Asia and the other in Europe. Let A be the event that the A
Virty [35]

Answer:

a)

0.5

option A

b)

0.6

c)

0.1

Step-by-step explanation:

The event A and B are independent so

P(A∩B)=P(A)*P(B)

P(A∩B)=P(0.2)*P(0.5)=0.10

a)

We have to find P(B'|A')

P(B'|A')=P(B'∩A')/P(A')

P(A)=0.2

P(A')=Asian project is not successful=1-P(A)=1-0.2=0.8

P(B)=0.5

P(B')=Europe project is not successful=1-P(B)=1-0.5=0.5

P(B'∩A')=Europe and Asia both project are not successful=P(A')*P(B')=0.8*0.5=0.4

P(B'|A')=P(B'∩A')/P(A')=0.4/0.8=0.5

This can be done by another independence property for conditional probability

P(B|A)=P(B)

P(B'|A')=P(B')

P(B'|A')=0.5

b)

Probability of at least one of two  projects will be successful means that the probability of success of Asia project or probability of success of Europe project  or probability of success of Europe and Asian project which is P(AUB).

P(AUB)=P(A)+P(B)-P(A∩B)

P(AUB)=0.2+0.5-0.1

P(AUB)=0.6

c)

Probability of only Asian project is successful given that at least one of the two projects is successful means that probability of success of project Asia while the project Europe is not successful denoted as P((A∩B')/(A∪B))=?

P((A∩B')/(A∪B))=P((A∩B')∩(A∪B))/P(A∪B)

P((A∩B')∩(A∪B))=P(A∩B')*P(A∪B)

P(A∩B')=P(A)*P(B')=0.2*0.5=0.10

P((A∩B')∩(A∪B))=0.1*0.6=0.06

P((A∩B')/(A∪B))=0.06/0.6=0.1

4 0
3 years ago
Any intelligent people want to tell me how the heck I do this
torisob [31]

Answer:

I'm pretty sure you are supposed to add the exponents.

Step-by-step explanation:

3 0
4 years ago
Solve each system using substitution. <br> -x^2-x+19=y<br> X=y+80
Softa [21]
sub <span> </span> since -x^2+x+19=y <span> </span> x=-x^2+x+19+80 <span> </span> x=-x^2+x+99 <span> </span> 0=-x^2+99 <span> </span> x^2=99 x=3√11

x=y+80
3√11=y+80
minus 80 both sides
-80+3√11=y

x=3√11
y=-80+3√11


solution
(x,y)
(3√11,-80+3√11)
8 0
4 years ago
Other questions:
  • Parallelogram FGHJ was dilated and translated to form
    11·2 answers
  • Hi its me again i need help <br> Math vs me i lose :(
    15·1 answer
  • *Simple math question* The eighth grade class at grade school has 15 girls and 14 boys. How many different boy-girl dates can be
    12·1 answer
  • Solve f=(sqrtg/l)/2pi for l
    15·1 answer
  • 4) BRAINLIEST AND 10 + POINTS! :)<br><br> PLS HELP ASAP
    6·1 answer
  • Need help!!!!!! I'm horrible at math!​
    13·2 answers
  • Select all the expressions that are equivalent to 4 - x.
    11·1 answer
  • Can someone please help me with #2,3,5 ( for Brainliest)
    12·1 answer
  • You have $5.60 to buy avocados for a guacamole recipe. Avocados cost $1.40 each.
    12·2 answers
  • What is greater 42.9 or 42.900 ANSWER PLSSSS
    10·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!