Sin (3x)cos(6x) - cos (3x) sin(6x)=-0.9

x=21.38602241

Step-by-step explanation:

Given: sin(3x)cos(6x) - cos(3x)sin(6x) = -0.9

Rewrite as difference identity: sin(3x-6x)=-0.9

Combine like terms in parentheses: sin(-3x)=-0.9

Take the inverse sine of both sides: -3x=-64.15806724

Divide both sides by -3: x=21.38602241

Refer to the sheet to see all trigonometric identities

b. y = 4x - 2

step-by-step explanation:

to find a parallel equation to an equation, make sure both equations have the same slope but different y-intercepts.

y = 4x + 1

4 = slope

1 = y-intercept

y = 4x - 2

4 = slope

-2 = y-intercept

they both have the same slope but different y-intercepts, so, b. is the correct answer.

and to check your work, you can graph both equations. : )