#Lim x to 1# f(x)=#(tan(pix))/(pi(x-1))# ?

1 Answer
Sep 13, 2017

#1#

Explanation:

making #y = x-1# we have

#tan(pi(y+1))/(pi y)=tan(pi y)/(pi y) = sin(pi y)/(pi y) 1/cos(piy)#

Now #x->1 rArr y->0# then

#lim_( x->1)(tan(pix))/(pi(x-1)) equiv lim_(y->0)sin(pi y)/(pi y) 1/cos(piy)=lim_(y->0)sin(pi y)/(pi y) lim_(y->0)1/cos(piy) = 1 xx 1 = 1#