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>
