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3 years ago

I need step by step help solving these problems (not just answers).

1 answer:

3 0

Secθ=-25/24 so cosθ=-24/25, sinθ=7/25 (quadrant 2) [√1-(24/25)²=√(625-576)/625=√(49/625)=7/25]
sin2θ=2sinθcosθ=-2×7×24/625=-336/625=-0.5376.
cos2θ=1-2sin²θ=1-2×49/625=527/625=0.8432.
tan2θ=sin2θ/cos2θ=-336/527 (=-0.6376 approx.)

The length of the third side is 12 making the Pythagorean triangle 5-12-13 (5²+12²=13²).
Assuming sinθ=5/13, then cosθ=12/13. sin2θ=2sinθcosθ=120/169; cos2θ=1-2sin²θ=1-50/169=119/169.
tan2θ=120/119.

Pythagorean triangle is 7-24-25. sinθ=2sin(θ/2)cos(θ/2), cosθ=1-2sin²(θ/2).
sin²θ=4sin²(θ/2)cos²(θ/2)=4sin²(θ/2)(1-sin²(θ/2)).
49/625= 4sin²(θ/2)-4sin⁴(θ/2); 4sin⁴(θ/2)-4sin²(θ/2)+49/625=0.
sin⁴(θ/2)-sin²(θ/2)+49/2500=0=(sin²(θ/2)-49/50)(sin²(θ/2)-1/50).
cosθ=1-2sin²(θ/2); 24/25=1-2sin²(θ/2), sin²(θ/2)=1/50, sin(θ/2)=1/(5√2)=√2/10.
cos(θ/2)=√1-1/50=7√2/10; tan(θ/2)=1/7.

(sin(x)cos(x))²=sin²(2x)/4.

This can be written cot(x)(cot(x)+1)=0. So cot(x)=0, x=π/2, 3π/2; or cot(x)=-1=1/tan(x), x=3π/4, 7π/4.

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Simplify 2(x - 4) + 7(x + 2). Step by step please

nasty-shy [4]

2(x - 4) + 7(x + 2)

mutiply the first bracket by 2

(2)(x)=2x

(2)(-4)= -8

mutiply the second bracket by 7

(7)(x)=7x

(7)(2)= 14x

2x-8+7x+14

2x+7x-8+14 ( combine like terms)

Answer:

9x+6 or 6+9x

7 0

4 years ago

Read 2 more answers

which of the following numbers which of the following numbers when added to it perfect squares is 240

Katena32 [7]

Answer:

first of all square mean two number or double so if we multiple 15×15=225 and if we multiply 16×16=256 mean the number 240 lies between them what about number 15.5 lets try now 15.5×15.5=240.25 if you want to make sure so just take a square root of this number

$\sqrt{240.25} = 15.5$

so 240 is product of (15.5)² note number after point is negligible

4 0

3 years ago

Read 2 more answers

the total attendance at a concert in a theater hall was 1500, of this total 400 were children,850 were women , and the remaining

AleksandrR [38]

Answer:

Below!

Step-by step explanation:

We know that:

400 + 850 + m = 1500

Solution of Question A:

Percent of children: Total children/Total attendance

=> 400/1500
=> 4/15
=> 0.27 (Rounded to nearest hundredth)
=> 0.27 x 100
=> 27%

Hence, the percent of children is about 27%.

Solution of Question B:

Percent of women: Total women/Total attendance

=> 850/1500
=> 85/150
=> 17/30
=> 17/30 x 100
=> 17/3 x 10
=> 170/3
=> 56.67%

Hence, the percent of women is 56.67%.

Solution of Question C:

400 + 850 + m = 1500
=> 1250 + m = 1500
=> m = 1500 - 1250
=> m = 250

Percent of men: Total men/Total attendance

=> 250/1500
=> 1/6
=> 0.17 (Rounded to nearest hundredth)
=> 0.17 x 100
=> 17%

Hence, the percent of men is about 17%

Hoped this helped.

$BrainiacUser1357$

3 0

2 years ago

Round 287.9412 to the nearest tenth. Do not write extra zeros

Debora [2.8K]

Heeellllooooo! :D

Let's take a look at this....

Hmmm.... 287.9412 huh? Now what we need to remember is that when rounding up we can only do that if the number is 5 or above 5.

We also need to know what place is the tenths place....
287.9412
^ there you have it!

Now if we look at the number before it.... it's a 4 but that is less than 5 so we need to round it down... our answer would be.... (drumroll please :D)

287.9 !

I hope this helps! :D

Please vote me for Brainliest if there is a second answer!

5 0

4 years ago

Read 2 more answers

Select the expression equivalent to 4(x - 7) + 8. A 4x - 47 + 8 B 4(x - 15) С 4x - 7 + 8 D 4x - 28 + 8

mote1985 [20]

Step-by-step explanation:

4(x - 7) + 8

= (4)(x) + (4)(-7) + 8

= 4x - 28 + 8. (D)

7 0

3 years ago