Question

If y = log((a^2 + √(a^2+x^2))/a) then dy/dx is: (Solve using trigonometrical substitution)​

Answer 1

Always Remember, for a real-valued function 'f',

$\sqrt{(f(x))^{2} } = |f(x)| ≠ f(x)$

But here, we just ignore the modulus sign on sec(theta) assuming as if sec(theta) is positive.

Hope, it'll help you...