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
katrin2010 [14]
2 years ago
12

use compound angle formulae to find sin 15 and cos 15 in form of [ surd a (surd b + c) ] . Hence, find tan 15 in the simplest su

rd form​
Mathematics
1 answer:
inysia [295]2 years ago
5 0

Answer:

see explanation

Step-by-step explanation:

Using the difference formulae for sine and cosine

sin(x - y) = sinxcosy - cosxsiny

cos(x - y) = cosxcosy + sinxsiny

sin15° = sin(45 - 30)°

sin(45 - 30)°

= sin45°cos30° - cos45°sin30°

= \frac{\sqrt{2} }{2} × \frac{\sqrt{3} }{2} - \frac{\sqrt{2} }{2} × \frac{1}{2}

= \frac{\sqrt{6} }{4} - \frac{\sqrt{2} }{4}

= \frac{\sqrt{6}-\sqrt{2}  }{4}

----------------------------------------------------------------------------------

cos15° = cos(45 - 30)°

cos(45 - 30)°

= cos45°cos30° + sin45°sin30°

= \frac{\sqrt{2} }{2} × \frac{\sqrt{3} }{2} + \frac{\sqrt{2} }{2} × \frac{1}{2}

= \frac{\sqrt{6} }{4} + \frac{\sqrt{2} }{4}

= \frac{\sqrt{6}+\sqrt{2}  }{4}

-------------------------------------------------------------------------------------

tan15° = \frac{sin15}{cos15}

= \frac{\sqrt{6}-\sqrt{2}  }{4} × \frac{4}{\sqrt{6}+\sqrt{2}  }

= \frac{\sqrt{6}-\sqrt{2}  }{\sqrt{6}+\sqrt{2}  }

Rationalise the denominator by multiplying numerator/ denominator by the conjugate of the denominator, that is (\sqrt{6} - \sqrt{2} )

= \frac{(\sqrt{6}-\sqrt{2})^2  }{(\sqrt{6}+\sqrt{2})(\sqrt{6}-\sqrt{2})    }

= \frac{6-4\sqrt{3}+2 }{6-2}

= \frac{8-4\sqrt{3} }{4}

= 2 - \sqrt{3}

You might be interested in
Is 8:12 equivalent to 10:15
kirill115 [55]
No it’s not because they don’t go into the same multiples
8 0
3 years ago
Read 2 more answers
Which of the following best describes the slope of the line below?
defon

Answer:

I think positive

Step-by-step explanation:

8 0
2 years ago
Read 2 more answers
real estate julie bought a house for $100,00 five years ago. if the value of the house has appreciated 5% per year , how much is
Stels [109]
To find the answer, turn the appreciated percent into a decimal:

5% ----> .05 (Divide by 100)

Then multiply it by the total value:

100,000 x .05 = 5000

Then add that to the total:

105,000

So the house is worth a total of $105,000.

Hope this helps!
5 0
3 years ago
In the diagram below secants PT & PU have been drawn from exterior point P such that the four arcs intercepted have the foll
fiasKO [112]

Answer:

  • x = 30°
  • RS = 30°, SR = TU = 120°, UR = 90°
  • ∠P = 45°
  • ∠UTS = 60°

Step-by-step explanation:

(a) If RS = x, then the sum of arcs around the circle is ...

  x + 4x +4x +3x = 360°

  12x = 360°

  x = 30°

__

(b) Based on the given ratios, the arc measures are computed from x. For example, ST = TU = 4x = 4(30°) = 120°

  • RS = 30°
  • ST = 120°
  • TU = 120°
  • UR = 90°

__

(c) Angle P is half the difference of arcs TU and RS:

  ∠P = (TU -RS)/2 = (120° -30°)/2

  ∠P = 45°

__

(d) Inscribed angle UTS is half the measure of the arc it intercepts. Arc RU has the measure (30° +90°) = 120°, so the measure of UTS is ...

  ∠UTS = 120°/2 = 60°

4 0
3 years ago
NEED HELP FAST PLEASE!!!
trasher [3.6K]
Answer: Choice B

The slope is rise/run = 2/3 meaning we go up 2 and over to the right 3. For instance, moving from (0,0) to (3,2) has us move up 2 and over to the right 3.

Alternatively you can use the slope formula m = (y2-y1)/(x2-x1) to get the same result of 2/3.
4 0
3 years ago
Read 2 more answers
Other questions:
  • Suppose that you draw two cards from a deck. After drawing the first card, you do not put the first card back in the deck. What
    10·1 answer
  • Which of the following has a graph that is a straight line?
    15·1 answer
  • Jackie exchanges 8 Kappa coins for 3 Gamma coins. Lana wants to exchange
    14·2 answers
  • Match the numerical expressions to their simplest forms
    12·2 answers
  • Assume that you are taking a seven​-question true or false quiz.
    8·1 answer
  • In order to make the expression below equivalent to ğ x + 6, which additional operation should be included in the
    5·1 answer
  • One hundred sixty people who suffer from painful diabetic neuropathy have volunteered to participate in a study. Eighty are sele
    15·1 answer
  • What is the standard form polynomial representing the volume of this shipping container?
    6·2 answers
  • ¨carlo packs 15 3/4 lb of books in 2 boxes. each box weighs 11/8 lb. there are 4 more books in box a than in box b. how many boo
    8·1 answer
  • If your scientific notation is 2.420 x 10° g (2.420 E 5 g), which direction would you move the decimal point to get the scientif
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!