What is the value of $$\frac{[(\sin x + \sin y) (\sin x - \sin y)]}{[(\cos x + \cos y) (\cos y - \cos x)]}?$$
$$\dfrac{[(\sin x + \sin y) (\sin x - \sin y)]}{[(\cos x + \cos y) (\cos y - \cos x)]}$$
=$$\dfrac{sin^{2}x-sin^{2}y}{cosxcosy-cosxcosy+cos^{2}x-cos^{2}y}$$
=$$\dfrac{sin^{2}x-sin^{2}y}{1-sin^{2}x-(1-sin^{2}y)}$$
=$$\dfrac{sin^{2}x-sin^{2}y}{sin^{2}x-sin^{2}y}$$
=1
Create a FREE account and get:
Quick, Easy and Effective Revision
By proceeding you agree to create your account
Free CAT Formulae PDF will be sent to your email address soon !!!
