Twelve is exactly in he four factors 12
Numerator
<span><span>cos<span>(<span>π/2</span>−x)</span></span>=<span>cos<span>(<span>π/2</span>)</span></span><span>cosx</span>+<span>sin<span>(<span>π/2</span>)</span></span><span>sinx</span></span>
now <span><span>cos<span>(<span>π/2</span>)</span></span>=0 and <span>sin<span>(<span>π/2</span>)</span></span>=1</span>
simplifies to : 0 + sinx = sinx
Denominator
<span><span>sin<span>(<span>π/2</span>−x)</span></span>=<span>sin<span>(<span>π/2</span>)</span></span><span>cosx</span>+<span>cos<span>(<span>π/2</span>)</span></span><span>sinx</span></span>
simplifies to : cosx + 0 = cosx
<span>⇒<span><span>cos<span>(<span>π/2</span>−x)</span></span><span>sin<span>(<span>π/2</span>−x)</span></span></span>=<span><span>sinx/</span><span>cosx</span></span>=<span>tan<span>x</span></span></span>
I'm going to assume that you're asking for the<em> equation</em> of that circle.
It's
<u>(x + 4)² + (y - 3)² = 16</u>
You should get constants to one side, and variables to the other. Like this:
4+4x=4x+7
Subtract 4x from left side: 4=4x+7-4x
Combine 4x, that would give you 0: 4=7
But... that isn't possible? I'm not completely sure, is the question just asking you to simplify?