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inessss [21]
3 years ago
12

Find the exact value of sin(-15)

Mathematics
1 answer:
koban [17]3 years ago
7 0
1)\ \ \ sin(- \alpha )=-sin \alpha \\2)\ \ \ cos2 \alpha =1-2sin^2 \alpha \ \ \ \Rightarrow\ \ \ 2sin^2 \alpha =1-cos2 \alpha \\\\ \Rightarrow\ \ \ sin \alpha = \sqrt{\frac{\big{1-cos2 \alpha}}{\big{2}}}  \\\\\\sin(-15^0)=-sin15^0=-\sqrt{\frac{\big{1-cos30^0}}{\big{2}}}  =-\sqrt{\frac{\big{1- \frac{ \sqrt{3} }{2} }}{\big{2}}} =-\sqrt{\frac{\big{2- \sqrt{3}}}{\big{4}}} =\\\\ =- \frac{1}{2}  \sqrt{2- \sqrt{3}}
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With which information can you construct more than one triangle?
madreJ [45]

Answer:

b & d

Step-by-step explanation:

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2 years ago
There is a triangular parking lot at the local mall. The second angle of the triangular parking lot is six more than twice as la
Travka [436]

Answer:

The measure of the three angles are;

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The second angle is 28°

The third angle is 90°

Step-by-step explanation:

The given information are;

The shape of the parking lot = Triangular

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First angle = A

Second angle = B

Third angle = C

The given triangle interior angle dimensions are;

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C = A + B

However, we have;

A + B + C = 180° (Angle sum property for a triangle)

Therefore;

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However, C = A + B  therefore;

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A + B = 90° (Symmetric property)

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6 + 3·B = 90°

3·B = 90° - 6° = 84°

B = 84°/3 = 28°

B = 28°

From, A = 6 + 2 × B, we have;

A = 6 + 2 × 28° = 62°

A = 62°

First angle = A = 62°

Second angle = B = 28°

Third angle = C = 90°

The measure of the three angles are;

First angle is 62°

Second angle is 28°

Third angle is 90°.

8 0
3 years ago
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slamgirl [31]

Answer:2/2/5

Step-by-step explanation:
If 3/4 = 9/5
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Hope this helped


4 0
2 years ago
Read 2 more answers
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Natali [406]
40x5= 200 I'm not sure who created five times more projects than the other, but whoever did, created 200 projects.
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3 years ago
If Rebecca reads 2pages per minute, how many pages could she read in 2 1/2 hours?
Mamont248 [21]

Answer:

300

Step-by-step explanation:

2*60 for 1 hr

120*2 to find two hrs

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add

3 0
2 years ago
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