how do i solve this?

Question

      lim(x→π/4) tanx⋅tan(π/4-x)=

Answer 1

tanx is defined when x = pi/4 so you can do direct substitution

 

tan(pi/4) - tan(pi/4 - pi/4)

 

tan(pi/4) - tan 0

 

1 - 0

 

1