Sin4xcos2x =
1/2sin6x + 1/2sin2x
1/2sin6x - 1/2sin2x
1/2cos2x + 1/2cos6x
1/2cos2x - 1/2cos6x

  1/2sin(6x) + 1/2sin(2x)

Step-by-step explanation:

You can look up the formulas for the product identities for sine and cosine, or you can guess and check using a graphing calculator. I did the calculator solution first (see the first attachment), then looked up the identities so I can tell you what they are (see the second attachment).

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These identities are based on the sum and difference angle identities:

  sin(α+β) +sin(α-β) = (sin(α)cos(β) +sin(β)cos(α)) + (sin(α)cos(β) -sin(β)cos(α))

  = 2sin(α)cos(β)

Dividing by 2 gives the identity of interest in this problem:

  sin(4x)cos(2x) = (1/2)(sin(4x +2x) +sin(4x -2x))

  sin(4x)cos(2x) = (1/2)(sin(6x) +sin(2x))

b is the answer that makes most sense

step-by-step explanation:

in problems involving proportions, we can use cross products to test whether two ratios are equal and form a proportion. to find the cross products of a proportion, we multiply the outer terms, called the extremes, and the middle terms, called the means.

hope it