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kumpel [21]
3 years ago
8

Plez the answer the subject is the double angle and half angle formula

Mathematics
1 answer:
soldier1979 [14.2K]3 years ago
8 0

Answer:

cos 2x = (√7) / 4

Step-by-step explanation:

sin x - cos x = 1/2

(sin x - cos x)² = (1/2)²

sin²x - 2 sin x cos x + cos² x = 1/4

1 - 2 sinx cosx = 1/4

2 sinx cosx = 3/4

sin 2x = 2 sinx cosx = 3/4

sin² 2x = 9/16

cos² 2x = 1 - sin² 2x = 1 - 9/16 = 7/16

cos 2x = (√7) / 4

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Del total de alumnos de una escuela de Medellín, la mitad nació en Medellín, un tercio en otros pueblos de Antioquia y los resta
lora16 [44]

Answer:

OK

Step-by-step explanation:

What language us That

5 0
3 years ago
At the movie theater, child admission is $5.30 and adult admission is 9.20. On Monday, four times as many adult tickets as child
AnnyKZ [126]
124 tickets sold at $9.20 = $1140.80
124÷4 =31
31 tickets sold at $5.30 = $164.30
$1140.80+$164.30=$1305.10
so so if you take the 124 tickets and divide it by 4 you get 31. The answer is 31 rickets were sold that day.
4 0
3 years ago
Find the sum of the first 100 terms in the series
iVinArrow [24]
Hello,

\dfrac{1}{n} - \dfrac{1}{n+1} = \dfrac{1}{n(n+1)} \\

 \dfrac{1}{1*2} = \dfrac{1}{1} - \dfrac{1}{2} \\

 \dfrac{1}{2*3} = \dfrac{1}{2} - \dfrac{1}{3} \\

 \dfrac{1}{3*4} = \dfrac{1}{3} - \frac{1}{4} \\

...\\
 \dfrac{1}{n*(n+1)} = \dfrac{1}{n} - \dfrac{1}{n+1} \\





Adding member by member, we have

\dfrac{1}{1*2} + \dfrac{1}{2*3} +\dfrac{1}{3*4} +...\dfrac{1}{n*(n+1)}=\\
 
\dfrac{1}{1}  - \dfrac{1}{n+1} \\

= \dfrac{n}{n+1} \\



if n=100 sum \boxed{= \dfrac{100}{101} }


3 0
3 years ago
Use the substitution method to solve the system of equations. choose the correct ordered pair.
slamgirl [31]

Answer:

D

Step-by-step explanation:

Since both equations express y in terms of x, equate the right sides

- 2x + 11 = - 3x + 21 ( add 3x to both sides )

x + 11 = 21 ( subtract 11 from both sides )

x = 10

substitute x = 10 into either of the 2 equations for y

y = - 2x + 11 = - 20 + 11 = - 9

solution is (10, - 9) → D


3 0
4 years ago
Read 2 more answers
Plezz help me I will mark you brainlyest!!!!!!!!!!!!!!!!!!!! ФФ
wlad13 [49]
(a) they spent $24.56 in total (to show ur work, you multiply 6.17(4)
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i’m so sorry i cant show the work but i hope this helps!
4 0
4 years ago
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