Question

prove sin²x×cos²y - cos²x×sin²y = sin²x - sin²y​

Answer 1

Answer:

${(sin \: x \: cos \: y)}^{2} - {(cos \: x \: sin \: y)}^{2} = \\ (sinx \: cosy \: + \: cosx \: siny)(sinx \: cosy \: - \: cosx \: siny) \\ \sin(x + y) \times \sin(x - y) = {sin}^{2} x \: - \: {sin}^{2} y \\ proved.$