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
k0ka [10]
3 years ago
10

Find an exact value.

" id="TexFormula1" title="cos(- \frac{ \77 \pi }{12}) " alt="cos(- \frac{ \77 \pi }{12}) " align="absmiddle" class="latex-formula">
Mathematics
1 answer:
xxTIMURxx [149]3 years ago
5 0
\cos\left(-\dfrac{7\pi}{12}\right)=\cos\dfrac{7\pi}{12}

Recall that

\cos^2x=\dfrac{1+\cos2x}2

Let x=\dfrac{7\pi}{12}, so that

\cos^2\dfrac{7\pi}{12}=\dfrac{1+\cos\dfrac{7\pi}6}2=\dfrac{1-\dfrac{\sqrt3}2}2=\dfrac{2-\sqrt3}4
\cos\dfrac{7\pi}{12}=\pm\sqrt{\dfrac{2-\sqrt3}4}=\pm\dfrac{\sqrt{2-\sqrt3}}2

Since the angle \dfrac{7\pi}{12} lies in the second quadrant, you know that the cosine must be negative, so

\cos\dfrac{7\pi}{12}=-\dfrac{\sqrt{2-\sqrt3}}2
You might be interested in
cougar park is shaped like a parallelogram and has an area of 1/16 sqaure mile. Its base is 3/8 mile. What is its height?
nikdorinn [45]
Divide 1/16 by 3/8 and do the rest I got confused
8 0
3 years ago
Read 2 more answers
A diameter of the sphere is MT CT CD
iren2701 [21]

Answer:

CT

Step-by-step explanation:

The diameter is the longest possible line through the sphere and passes through the center.

3 0
3 years ago
2x=3y+1/2 I have to write this in standard form and slope intercept form
Sav [38]

Answer:

Step-by-step explanation:

2x = 3y + 1/2

standard : Ax + By = C

2x = 3y + 1/2....multiply everything by 2 to get rid of the fractions

4x = 6y + 1 ....subtract 6y from both sides

4x - 6y = 1 <==

slope intercept : y = mx + b

2x = 3y + 1/2....subtract 1/2 from both sides

2x - 1/2 = 3y....divide everything by 3

2/3x - 1/6 = y...rearrange

y = 2/3x - 1/6 <===

8 0
3 years ago
Shen is saving money to buy a game. The game costs $24 , and so far he has saved two-thirds of this cost. How much money has She
valentinak56 [21]
24 divided by 3 = 8

but thers two third so 8+8=16

shen has saved $16.00

Hope this helps!
8 0
3 years ago
Simplify. 5 - 2(x - 3)
V125BC [204]
To solve this, we simply need to remember our rules about order of operations. They tell us that first, we should distribute the 2 with the rest of the parentheses.

5-2(x-3)
5-2x+6

Next, we should combine our like-terms.

5-2x+6
11-2x

Seeing as we do not know the value of the variable, the simplest form of the expression is 11-2x.
3 0
3 years ago
Other questions:
  • Can you guys plz help me quick What is 4y - 8
    6·1 answer
  • Find the measure of angle x in the figure below: Two triangles are shown such that one triangle is inverted and they share a com
    11·1 answer
  • When Lafayette led the column, the troops marched 24 miles in 6 hours. Then he left and the troops reduced their speed by 1 mile
    14·2 answers
  • Janice just got a 5% raise, so her hourly pay increased by
    7·1 answer
  • The points (-3,-1) and (-3,5) are adjacent vertices of a rectangle. Two of the sides of the rectangle have a length of 8 units.
    14·1 answer
  • PLEASE HELP ME LINK IS BELOW
    7·2 answers
  • An equation of a line parallel to y=-9/5x-3 and goes through (1,7)
    15·1 answer
  • Jon recently drove to visit his parents who live 270 270 miles away. On his way there his average speed was 24 24 miles per hour
    12·1 answer
  • This net could be folded to form a This figure will have v faces vertices. edges, and a​
    7·2 answers
  • Which diagram has all of the correct lines of reflectional symmetry for the regular pentagon? A pentagon has 3 lines of reflecti
    7·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!