Question

cos h²x - sinh²x = 1 prove that​

Answer 1

Step-by-step explanation:

${ (\frac{ {e}^{x} + {e}^{ - x} }{2} })^{2} - ({ \frac{ {e}^{x} - {e}^{ - x} }{2} })^{2}$

$\frac{ {e}^{2x} + 2 + {e}^{ - 2x} - {e}^{2x } + 2 - {e}^{ - 2x} }{4}$

$\frac{4}{4}$

$1$