What is the domain and range of # y=secx#?

1 Answer
Nov 25, 2017

Domain: #x in RR | x != (npi+pi/2)#
Range: # y <= -1 uu y>=1 or y| (-oo,-1)uu(1,oo) #

Explanation:

#y=sec x or y= 1/cosx :. sec x# is undefined at #cosx=0#

#cos (npi+pi/2)=0 :. x != (npi+pi/2)# Thus, the domain of the

secant function is the set of real numbers excluding

#x = (npi+pi/2) #​ i.e Domain: #x in RR | x != (npi+pi/2)#

Range: cosine function only takes values that are between #−1# and

#+1#. So #secx# can only take values that are #>=1 or <=-1 :.#

Range: # y <= -1 uu y>=1 or y| (-oo,-1)uu(1,oo) #

graph{secx [-10, 10, -5, 5]} [Ans]