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3 years ago

Complete the identity. sin4x - cos4x = ?

Mathematics

2 answers:

xenn [34]3 years ago

5 0

Answer:

1-2cos^2x

Step-by-step explanation:

I took the test and got it correct

Katyanochek1 [597]3 years ago

4 0

Since sin(2x)=2sinxcosx, we can plug that in to get sin(4x)=2sin(2x)cos(2x)=2*2sinxcosxcos(2x)=4sinxcosxcos(2x). Since cos(2x) = cos^2x-sin^2x, we plug that in. In addition, cos4x=cos^2(2x)-sin^2(2x). Next, since cos^2x=(1+cos(2x))/2 and sin^2x= (1-cos(2x))/2, we plug those in to end up with 4sinxcosxcos(2x)-((1+cos(2x))/2-(1-cos(2x))/2)
=4sinxcosxcos(2x)-(2cos(2x)/2)=4sinxcosxcos(2x)-cos(2x)
=cos(2x)*(4sinxcosx-1). Since sinxcosx=sin(2x), we plug that back in to end up with cos(2x)*(4sin(2x)-1)

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Answer:

2, 16 and 256.

Step-by-step explanation:

Just substitute for n:-

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3 years ago

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Answer:

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3 years ago

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Mandarinka [93]

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3 years ago

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Tatiana [17]

F(x) is the same as y.......so basically ur subbing in ur points into the equation to see if it comes out equal.

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and that is how to do this problem.....

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3 years ago

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GenaCL600 [577]

Answer:

Step-by-step explanation

6+1=7

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Read 3 more answers