Which statement is a example of a theorem? a line is an infinite set of points that extends in opposite directions,

Mathematics

1 answer:

adelina 88 [10]3 years ago

8 0

Most car accidents happen at night

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What are the mean and the mode of the following set of data: 5, 12, 1, 5, 7

Alika [10]

Mean: so basically you add up all the numbers (5+12+1+5+7=30) and divide the sum (30) with how many numbers there are (5) so 30/5=6

mode: mode is numbers repeated, since there are two 5's it is the mode (you may also have multiple modes)

3 0

3 years ago

Read 2 more answers

1+4=5 2+5=12 3+6=21 8+11=?

g100num [7]

I think the pattern is that you multiply the first number by the second , then add the first number. SO:
e.g. for the first one 1 x 4 = 4 , 4 + 1 = 5
for the second one 2 x 5 = 10, 10 + 2 = 12...
So for 8+11:
you do 8 x 11 = 88 , 88 + 8 = 96

7 0

3 years ago

Cos^2 x+4sin^2 x/2=1

lana [24]

$Let\ \dfrac{x}{2}=a,\ therefore\ x=2a.\\\\\cos^2x+4\sin^2\dfrac{x}{2}=\cos^22a+4\sin^2a\\\\\text{use}\ \cos2x=\sin^2x-\cos^2x\\\\=(\sin^2a-\cos^2a)^2+4\sin^2a\\\\\text{use}\ (a-b)^2=a^2-2ab+b^2\\\\=(\sin^2a)^2-2(\sin^2a)(\cos^2a)+(\cos^2a)^2+4\sin^2a\\\\=\sin^4a-2\sin^2a\cos^2a+\cos^4a+4\sin^2a\\\\=\underbrace{\sin^4a+2\sin^2a\cos^2a+\cos^4a}_{(*)}-4\sin^2a\cos^2a+4\sin^2a\\\\\text{use}\ (*)\qquad(a+b)^2=a^2+2ab+b^2$

$=\underbrace{(\sin^2a)^2+2\sin^2a\cos^2a+(\cos^2a)^2}_{(*)}-4\sin^2a(\cos^2a-1)\\\\=(\sin^2a+\cos^2a)^2-4\sin^2a(\cos^2a-1)\\\\\text{use}\ \sin^2a+\cos^2a=1\to\sin^2a=\cos^2a-1\\\\=1^2-4\sin^2a(\sin^2a)=1-4\sin^4a=1-(2\sin^2a)^2$

$\cos^22a+4\sin^2a=1\\\\1-(2\sin^2a)^2=1\qquad\text{subtract 1 from both sides}\\\\-(2\sin^2a)^2=0\to2\sin^2a=0\qquad\text{divide both sides by 2}\\\\\sin^2a=0\to\sin a=0\\\\a=k\pi\ for\ k\in\mathbb{Z}\\\\\dfrac{x}{2}=k\pi\qquad\text{multiply both sides by 2}\\\\\boxed{x=2k\pi\ for\ k\in\mathbb{Z}}$