If cos(a+b)=4÷5 and sin (a-b)5÷13, where \'a\' lies between 0 and 45degree ,find the value of tan2a.

If cos(a+b)=4÷5 and sin (a-b)5÷13, where \'a\' lies between 0 and 45

1.	If cos(a+b)=4÷5 and sin (a-b)5÷13, where \'a\' lies between 0 and 45degree ,find the value of tan2a.
Answer»