Question

( begin{aligned} & tan (45+theta) cdot tan (45-theta) =&left(frac{tan 45+tan theta}{1-tan 45 tan theta}right) cdotleft(frac{tan 45-tan theta}{1+tan 45 tan theta}right) =&left(frac{1+tan theta}{1-tan theta}right)left(frac{1-tan theta}{1+tan theta}right) =& frac{1}{1} end{aligned} )

# tan(45°+ 0). tan (45° - 0) = a) 0 b) 1

Solution