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April 28, 2016
Posted by **Tom** on Sunday, June 17, 2012 at 10:32am.

lim cos(x + pi/2)/x

x->0

- Calculus -
**Reiny**, Sunday, June 17, 2012 at 12:29pmcos(x+pi/2)

= cosx cos pi/2 - sinx sin pi/2

= 0 - sinx

= -sinx

so

limit cos(x+pi/2)/x as x----> o

= lim -sinx/x , x ---> 0

= -1

using the fact that lim sinx/x = 1