Question

prove that tan² A -tan² B = Cos² B - cos² A / cos² A . cos² B​

Answer 1

Answer:

RHS = cos²B / cos²A cos²B - cos²A / cos²A cos²B

        = 1/cos²A  -    1/cos²B

        = sec²A - sec²B

         = 1 + tan²A - 1 - tan²B

          = tan²A - tan²B  = LHS

         hence proved

Step-by-step explanation:

Answer 2

Answer:

Step-by-step explanation: