Sin(13π/8) , is in quadrant IV so the angle will be negative, find the reference angle.
<span>sin(13π/8) = -sin(16π/8 - 13π/8) = -sin(3π/8) = -cos(4π/8 - 3π/8) = - cos(π/8). </span>
<span>Use half angle formula for cos(x): </span>
<span>cos²(x/2) = (cos(x) + 1) / 2 </span>
<span>Let x = π/4 </span>
<span>cos²(π/8) = (cos(π/4) + 1) / 2 </span>
<span>cos²(π/8) = (√(2) / 2 + 1) / 2 </span>
<span>cos(π/8) = √(√(2) / 4 + 1/2) </span>
<span>-cos(π/8) = -√((√(2) + 2) / 4)</span>
So...
= (5x-12) - (3x+18)
= 5x - 12 - 3x - 18
= 2x - 30
I believe that's the answer
Answer:
x=(k+3)/y
Step-by-step explanation
First, we simplify by adding 3 to both sides of the equation
xy-3+3=k+3
Now it's xy=k+3
To get x we divide both sides by y
So x=(k+3)/y
Answer:
The expression is not factorable with rational numbers
Step-by-step explanation:
<span> (x − 4)(x2 + 3x − 1)
=</span><span>x^3 + 3x^2 - x -4x^2 - 12x +4
=</span>x^3 -x^2 - 13x +4
answer is <span>B.x^3-x^2-13x+4</span>
