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
ludmilkaskok [199]
2 years ago
9

Prove that cos^4∆ - sin^4∆ = 2cos^2∆ - 1

Mathematics
1 answer:
GarryVolchara [31]2 years ago
3 0

\cos^{4} x-\sin^{4} x\\\\=(\cos^{2} x+\sin^{2} x)(\cos^{2} x-\sin^{2} x)\\\\=\cos^{2} x-\sin^{2} x\\\\=\cos^{2} x-(1-\cos^{2} x)\\\\=2\cos^{2} x-1

You might be interested in
With water from one hose, a swimming pool can be filled in 9 hours. A second, larger hose used alone can fill the pool in 2 hour
Monica [59]

1/9 + 1/2 = 1/x

Let x = length of time it will take both hoses to work together

Multiply both sides by 18x.

2x + 9x = 18

10x = 18

x = 18/10

x = 9/5

x = 1.8 hours

In other words, if both hoses work together, the pool can be filled in 1 hour and 48 minutes.

5 0
3 years ago
A college is currently accepting students that are both in-state and out-of-state. They plan to accept three times as many in-st
ziro4ka [17]

Answer:

0 < x ≤ 100 and 0 < y ≤ 300

Step-by-step explanation:

THIS IS THE COMPLETE QUESTION BELOW;

college is currently accepting students that are both in-state and out-of-state. They plan to accept three times as many in-state students as out-of-state, and they only have space to accept 100 out-of-state students. Let x = the number of out-of-state students and y = the number in-state students. Write the constraints to represent the incoming students at the college.

0 < x ≤ 100 and 0 < y ≤ 300

x > 0 and y > 0

0 < x ≤ 100 and y > 300

0 < x and y < 100

SOLUTION

they only have space to accept 100 out-of-state students,which means that the Maximum number of out-of-state students that can be accepted is 100

Then x= 100(Maximum number of out-of-state students that can be accepted)

They plan to accept three times as many in-state students as out-of-state which means that

Y = 3x(Maximum number of in-state students)

Then we can deduced that the numbee out-of-state students that can be accepted can lyes between the range of 0 and 100 which means from interval 0 to 100

Which can be written as 0 < x ≤ 100

But we need to know the interval for the Maximum number of in-state students(Y), to do that we need to multiply the equation above by 3 since Y = 3x

0 < x ≤ 100

3× 0 = 0

3× X = X

3× 100= 300

Then 0 < 3x≤ 300

But we know that Y = 3x then substitute into last equation

We have

0 < y ≤ 300

ThenBthe constraints to represent the incoming students at the college is

0 < x ≤ 100 and 0 < y ≤ 300

8 0
3 years ago
Nnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn<br>n
lianna [129]

Answer:

That is not a question

Step-by-step explanation:

This is not a question that we can solve please put a REAL problom if you ever need help!

4 0
3 years ago
Given: sin ∅= 4/5 and cos x = -5/13 ; evaluate the following expression.<br><br> tan( ∅ - x )
Pavlova-9 [17]

By definition of tangent,

tan(θ - x) = sin(θ - x) / cos(θ - x)

Expand the sine and cosine terms using the angle sum identities,

sin(x ± y) = sin(x) cos(y) ± cos(x) sin(y)

cos(x ± y) = cos(x) cos(y) ∓ sin(x) sin(y)

from which we get

tan(θ - x) = (sin(θ) cos(x) - cos(θ) sin(x)) / (cos(θ) cos(x) + sin(θ) sin(x))

Also recall the Pythagorean identity,

cos²(x) + sin²(x) = 1

from which we have two possible values for each of cos(θ) and sin(x):

cos(θ) = ± √(1 - sin²(θ)) = ± 3/5

sin(x) = ± √(1 - cos²(x)) = ± 12/13

Since there are 2 choices each for cos(θ) and sin(x), we'll have 4 possible values of tan(θ - x) :

• cos(θ) = 3/5, sin(x) = 12/13 :

tan(θ - x) = -56/33

• cos(θ) = -3/5, sin(x) = 12/13 :

tan(θ - x) = 16/63

• cos(θ) = 3/5, sin(x) = -12/13 :

tan(θ - x) = -16/63

• cos(θ) = -3/5, sin(x) = -12/13 :

tan(θ - x) = 56/33

7 0
2 years ago
Read 2 more answers
How Do You Do This?????????????????????
sp2606 [1]
2/9  ×  3 =

= 2×3 / 9 = 

= 6/9 = 

= 2/3
5 0
3 years ago
Read 2 more answers
Other questions:
  • scott is riding a bike course that is 50 miles long. So far, he has ridden 6 miles of the course. What percentage of the course
    5·1 answer
  • What solid figure has congruent squares on all six sides
    10·1 answer
  • 5 baseballs to 25 softballs in simplest form
    10·1 answer
  • Sarita showed the steps to solving the equation. 5 (x minus 3) + 7 (x + 4) = 73 Steps Sarita's Solution Sarita's Verification 1
    15·2 answers
  • What is the range of the function y= 2sinx​
    11·2 answers
  • What does 2x-y^3 equal?
    10·1 answer
  • Jim and Henry were searching in the freezer for ice cream. They found 1.243 pints of chocolate chip ice cream and 2.54 pints of
    5·2 answers
  • Your friend is investing in a 401(k) that promises 2% annual growth. He plans on investing $250 each month for 25 years. Excel r
    12·1 answer
  • There are 180 dogs. If 35% of them are huskies, how many huskies are there? *<br> Your answer
    6·1 answer
  • What is 2x2 i need help
    13·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!