answer.
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
puteri [66]
2 years ago
7

What is the proof the formula for cos(A+B)=cosAcosB-sinAsinB?

Mathematics
1 answer:
brilliants [131]2 years ago
8 0
Given data, cos(A - B) = cosAcosB + sinAsinB 
<span>let, A=60' and B=30' ( here the ' sign bears degree) </span>
<span>L.H.S = cos(A - B) </span>
<span>=cos (60'-30) ( using value of A and B ) </span>
<span>=cos30' </span>
<span>= sqrt3/2 </span>
<span>R.H.S= cosAcosB + sinAsinB </span>
<span>=cos60' cos30' + sin60' sin30' </span>
<span>= 1/2* sqrt3/2+ sqrt3/2*1/2 </span>
<span>= sqrt3/4 + sqrt3/4 </span>
<span>=2 sqrt3/4 </span>
<span>= sqrt3/2 </span>
<span>so L.H.S =R.H.S or cos(A - B) = cosAcosB + sinAsinB</span>
You might be interested in
Determine which equations below, when combined with the equation 3x-4y=2, will form a system with no solutions. Choose all that
svetoff [14.1K]
Two equations will not have solution if they are parallel and have different y-intercepts. Parallel lines have the same slope. In a slope-intercept form, the equation of the line can be expressed as,       
 
        y = mx + b 

where m is slope and b is the y-intercept.

Given: 3x - 4y = 2
Slope-intercept: y = 3x/4 - 1/2

A. 2y = 1.5x - 2
Slope-intercept: y = 3x/4 - 1

B. 2y = 1.5x - 1
Slope-intercept:  y = 3x/4 - 1/2

C. 3x + 4y = 2
Slope-intercept:  y = -3x/4 + 1/2

D. -4y + 3x = -2
Slope-intercept: y = 3x/4 + 1/2

Hence, the answers to this item are A and D. 
6 0
2 years ago
Are the following statements true or false? 1. If F⃗ is a vector field in 3-dimensional space, and W is a solid region with boun
Masteriza [31]

Answer:

Step-by-step explanation:

1) True. This is because the divergence of F is 1, thus, F is a linear function. Orientation is given outward to the surface. Linear function double integrated over a surface with outward orientation gives volume enclosed by the surface.

2) True. This is primarily what the Divergence theorem is.

3) False. If F was 3/pi instead of div(F), then the statement would have been true.

4) False. The gradient of divergence can be anything. The curl of divergence of a vector function is 0, not the gradient o divergence.

5) False. While finding Divergence, derivatives are taken for different variables. Since the derivatives of constants are 0, therefore, both the vector functions F and G can be different constant parts of there components even if their divergences are equal.

8 0
2 years ago
James purchased five bonds of face value of $1,000 that paid 5% annual interest rate. the total annual interest income of james
Trava [24]
Given:
5 bonds of face value of 1,000 that paid 5% annual interest rate.

5 bonds x 1,000 = 5,000
5,000 x 5% x 1 year = 250

The total annual interest income of James is 250. Each bond earns 50 per annum.
8 0
2 years ago
Read 2 more answers
The monthly salary of Mr. Sachdev gets increased by 5%, thereby his salary becomes Rs. 15,120 per annum, His earlier monthly sal
Elan Coil [88]
1. x = 15120/12 = 1260 (monthly salary)
2. 1200 x 0.05 = 60 (raise)
Check: 1200+60=1260
6 0
2 years ago
Point Z is equidistant from the vertices of ΔTUV.
nadya68 [22]

Answer:

option C. Angle BTZ Is-congruent-to Angle BUZ

Step-by-step explanation:

Point Z is equidistant from the vertices of triangle T U V

So, ZT = ZU = ZV

When ZT = ZU  ∴ ΔZTU is an isosceles triangle ⇒ ∠TUZ=∠UTZ

When ZT = ZV  ∴  ΔZTV is an isosceles triangle ⇒ ∠ZTV=∠ZVT

When ZU = ZV  ∴ ΔZUV is an isosceles triangle ⇒ ∠ZUV=∠ZVU

From the figure ∠BTZ is the same as ∠UTZ

And ∠BUZ is the same as ∠TUZ

So, the statement that must be true is option C

C.Angle BTZ Is-congruent-to Angle BUZ

3 0
2 years ago
Read 2 more answers
Other questions:
  • What are two partial products you could add to find 990x37
    7·2 answers
  • why polar coordinates seem better suited for circular-type functions, while the rectangular coordinate system seems better suite
    7·1 answer
  • What is the following sentence written as an expression add the product of 3 and 6 to 4
    13·1 answer
  • Which is the simplified form of the expression (StartFraction (x Superscript negative 3 Baseline) (y squared) Over (x Superscrip
    12·2 answers
  • Veronique and Lily compare their investment accounts to see how much they will have in the accounts after seven years. They subs
    5·1 answer
  • A group of college DJs surveyed students to find out what music to plan for their upcoming parties. Thirty percent of the studen
    7·1 answer
  • Triangle ABC has been reflected over the y- axis to create triangle A’B’C’. Which of the following statements is true ? B’C’ = 2
    10·1 answer
  • Consider the numbers z = StartRoot 2 EndRoot (cos 45o + i sin 45o )and w = 2(cos 90o + i sin 90o).
    13·2 answers
  • A single bus fare costs $2.35. A monthly pass costs $45.75. Celine estimates that she will ride the bus 25 times this month. Kam
    7·1 answer
  • In a given survey, 9 people said their favorite color is pink. This number represented 45% of the total people. How many total p
    15·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!