I am unable to find the answer of this question. Any help will be appreciated
If A^2 + B^2 =1 then find the range of (a+b) where a and b is real.
Assuming you haven't done geometry of the circle you can think of it this way.
$\displaystyle A^2+B^2=1$
$\displaystyle A^2=1-B^2$
$\displaystyle A=\sqrt{1-B^2}$
Think of the maximum and minimum vales of B so that A is real. Then do the same thing for A instead of B.