Rewrite with only sin x and cos x.

Mathematics

2 answers:

Rudik [331]3 years ago

5 0

Answer:

A. 2 sinx cosx - 1 + 2 sin^2 x.

Step-by-step explanation:

sin2x = 2 sinx cosx

cos2x = cos^2x - sin^2x

So sin2x - cos2x = 2 sinx cosx - ( cos^2x - sin^2x)

But cos^2 x = 1 - sin^2 x, so we have:

2 sinx cosx - (1 - sin^2 x - sin^2x)

= 2 sinx cosx - 1 + 2 sin^2 x.

timurjin [86]3 years ago

3 0

Answer:

A. 2·sin(x)·cos(x) - 1 + 2·sin^2(x)

Step-by-step explanation:

The double angle identities can be use directly:

sin(2x) = 2sin(x)cos(x)
cos(2x) = 1 - 2sin^2(x)

The difference of these is ...

sin(2x) -cos(2x) = 2sin(x)cos(x) -(1 -2sin^2(x)) = 2sin(x)cos(x) -1 +2sin^2(x)

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So this plane is made up of three points, names E, D and B. (Edit: This plane may be made up of four points, because of point A.)

E and B are collinear with A. This basically means that they all are on the same line.

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CD and FD are called rays. See those little lines above them? I’ll be sure to attached another image so that you know what I’m taking about. Anyway, that means they are rays. Rays are like never ending lines; they start at a point and the line will go on for infinity.

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Whelp, that’s all I’ve got! Good luck!!

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