Question

SecA+tanA =m and secA-tanA=n so fnd value of √mn

Answer 1

take a look at the answer of the question

Answer 2

SecA+tanA = m .....1
SecA-tanA = n. ......2

multiply 1 and 2
(SecA+tanA)(SecA-tanA) = mn
Sec^2 A - tan^2 A = mn
$\sqrt{mn } = \sqrt{ { \sec }^{2}a - { \tan }^{2} a }$