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2 years ago

Show that each statement is true: Cos^4X-sin^4X=2cos^2X-1

1 answer:

Ivan2 years ago

4 0

$cox^4x-sin^4x=2cos^2x-1\\\\
(cosx^2-sin^2x)(cosx^2x+sin^2x)=2cos^2x-1\\\\
cosx^2-sin^2x*1=2cos^2x-1\ \ \ | subtract\ 2cos^2x\\\\
-cosx^2-sin^2x=-1\ \ \ | multiply\ by\ -1\\\\
cosx^2+sin^2x=1\\\\
1=1$

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I REALLY NEED HELP

garri49 [273]

Look at the picture.

1.
$y=mx+b\\\\m=\dfrac{9}{3}=3\\\\b=4\\\\\boxed{f(x)=3x+4}$

2.
$f(x)=-2x+3\\\\for\ x=-2\to f(-2)=-2\cdot(-2)+3=4+3=7\to(-2;\ 7)\\for\ x=-1\to f(-1)=-2\cdot(-1)+3=2+3=5\to(-1;\ 5)\\for\ x=0\to f(0)=-2\cdot0+3=3\to(0;\ 3)\\for\ x=1\to f(1)=-2\cdot1+3=-2+3=1\to(1;\ 1)$

3.
$y=mx+b\\\\m=\dfrac{3}{6}=\dfrac{1}{2}=0.5\\\\b=-3\\\\\boxed{f(x)=0.5x-3}$
$for\ x=-6\to f(-6)=-6\\for\ x=-2\to f(-2)=-4\\for\ x=0\to f(0)=-3\\for\ x=6\to f(6)=0$

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3 years ago

A football field is 120 yards long and 160 yards wide. How many square yards of grass is needed to cover the field? Show your ca

sleet_krkn [62]

Answer:

19,200 yds²

Step-by-step explanation:

The question is asking for how many square yards of grass is needed

This means that it is looking for the Area.

The formula for area is Length x Width = Area

120 (Length)

160 (Width)

120 x 160 = 19,200

The unit of measurement is yards...

19,200 yds²

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Step-by-step explanation:

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