Ask about Trigonometric Identities.
Recall trigonometric identities
Use trigonometric identity sin2x + cos2x = 1.
Recall trigonometric identities
Think about Trigonometric Identities.
\\(\\frac {cos \\theta}{1-tan \\theta} - \\frac{sin^2 \\theta}{cos \\theta - sin \\theta} = \\frac {cos^{2} \\theta-sin^2 \\theta}{cos \\theta-sin \\theta} = cos \\theta + sin \\theta \\)
\\(\\frac{cot^2 \\theta \\left ( sec \\theta -1 \\right)}{1 + sin \\theta} + \\frac{sec^2 \\theta \\left (sin \\theta - 1 \\right)}{1 + sec \\theta}= \\frac {cot^{2} \\theta \\left ( sec \\theta - 1 \\right )\\left ( sec \\theta + 1 \\right ) + sec^{2} \\theta \\left ( sin \\theta-1 \\right )\\left ( sin \\theta+1 \\right )}{\\left ( 1+sin \\theta \\right )\\left ( 1+sec \\theta \\right )} \\)
= \\( \\frac {cot^{2} \\theta \\left ( sec^{2} \\theta - 1 \\right ) + sec^{2} \\theta \\left ( sin^{2} \\theta-1 \\right)}{\\left ( 1+sin \\theta \\right )\\left ( 1+sec \\theta \\right )}\\)
= \\(\\frac {cot^{2} \\theta tan^{2} \\theta - sec^{2} \\theta cos^{2} \\theta}{\\left ( 1+sin \\theta \\right )\\left ( 1+sec \\theta \\right )}\\)
= \\(\\frac { 1 - 1}{\\left ( 1+sin \\theta \\right )\\left ( 1+sec \\theta \\right )} = 0\\)
