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WINSTONCH [101]
2 years ago
8

PLEASE HELP ME!!! I don’t understand

Mathematics
2 answers:
s344n2d4d5 [400]2 years ago
8 0

Answer:

see explanation

Step-by-step explanation:

Using the addition formula for cosine

cos(x ± y) = cosxcosy ∓ sinxsiny

and exact values

sin45° = cos45° = \frac{\sqrt{2} }{2}

c0s30° = \frac{\sqrt{3} }{2} , sin30° = \frac{1}{2}

Express cos15° = cos(45 - 30 )°, then

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} ← exact value

ElenaW [278]2 years ago
6 0

Answer:

   √6 + √2

= --------------

        4

Step-by-step explanation:

15° = 45° - 30°

So

cos(15)  = cos(45 - 30)

=cos(45)  × cos(30) + sin(45) × sin(30)

= 1/√2  × (√3)/2  + 1/√2 × 1/2

    (√3) + 1

= --------------

     2√2

    (√3) + 1              √2

= -------------- x       ---------

     2√2                  √2

   √6 + √2

= --------------

        4

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2 years ago
What is the difference between a right, acute, and obtuse triangle?
kakasveta [241]

A right triangle has one angle that's 90° and a corner that looks like an L. Obtuse triangles have one angle that's greater than 90°. In acute triangles, all the angles are less than 90°.

Step-by-step explanation:

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3 years ago
Read 2 more answers
Write -4i+(1/4-5i)-(-3/4+8i)+17i as a complex number in the standard for
KatRina [158]

Answer:

1+ 0i

Step-by-step explanation:

A complex number is a number which has some real part and some imaginary part.

Standard form of a complex number is represented as

a +bi

Where a is the real part,

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And i = \sqrt{-1}

Given complex number:

-4i+\dfrac{1}{4}-5i)-(-\dfrac{3}{4}+8i)+17i\\\Rightarrow -4i+\dfrac{1}{4}-5i + \dfrac{3}{4}-8i+17i\\\Rightarrow  \dfrac{3}{4}+\dfrac{1}{4}-4i -5i-8i+17i\\\Rightarrow  \dfrac{3+1}{4}-17i+17i\\\Rightarrow \dfrac{4}{4}+0i\\\Rightarrow 1 + 0i

Hence, the standard form is 1+ 0i.

8 0
2 years ago
Am I right or wrong plz help
ElenaW [278]

you are corret i hope

i helped

7 0
3 years ago
PLEASE HELP I WILL MARK BRILLIANT WHOEVER CAN ANSWER this question And I will only accept if you explain with a well answer Than
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