Question

If cos(a+b)=4/5 ,sin(a-b)=5/13 and a and b lies between 0 and pi then find tan2a

Answer 1

Cos (a+b) = 4/5

a + b = 0.6435  ------- (i)


Sin (a-b) = 5/13

a-b = 0.39479 ----------- (ii)


Add (i) to (ii)


2a = 1.0383 


Tan2a =  Tan 1.0383

          = 1.697

Answer 2

Step-by-step explanation:

$\huge \rm \tan2a = 1.6$