213 points OSCAT1 94224 Consider the following tanTrt 1 1 t

21.3 points OSCAT1 9.4.224 Consider the following. tan(Tr.-t) = 1 1 tan() + tan(t) Prove the identity. tan4tan() . tan(t) 1tan(t) Additional Materials eBook Sum to Product Identities Sum to Product and Product to Sum Identities O Type here to search

Solution

tan ( pi/4 - t ) = ( 1- tan t ) / ( 1 + tan t )

tan ( pi/4 - t ) = ( tan pi/4 - tan t ) / ( 1 + tan pi.4 * tan t )

= ( 1 - tan t ) / ( 1+ 1* tan t )

= ( 1 - tan t ) / ( 1 + tan t )

hence proved!