sinh ( x + y ) cosh ( x - y ) is equal to

sinh(x+y)cosh(x-y) is equal to
  1. 12(sinh2x+sinh2y)
  2. (sinh2x+sinh2y)
  3. 12(sinh2x-sinh2y)
  4. (sinh2x-sinh2y)

Solution

We know, 2sinhxcoshy=(sinh(x+y)+sinh(x-y))

Or, sinhxcoshy=12(sinh(x+y)+sinh(x-y))

⇒sinh(x+y)cosh(x-y)=12[sinh(x+y+x-y)+sinh(x+y-x+y)]

=12(sinh2x+sinh2y)

Asked in: AP EAMCET 2021 (20 Aug Shift 2)

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