Question #b639f

1 Answer
Dec 17, 2017

Assumption: you mean #f(x)=-2sin(x)#

see explanation

Explanation:

Set #y=-2sin(x)#

Assuming #x# is in radians

#y_1=sin(x)#

#y_2=2xxy_1=2xxsin(x)->2sin(x)#

Max #y# value of #sin(x)# is #+-1#
So max #y# value of #2sin(x)# is #+-2#

Making #2sin(x)# become #-2sin(x)# just turns #2sin(x)# upside down( reflected about the x-axis).

There are #2pi# radians in a circle so as we have not changed #x# in any way the wave form repeats every #+-2pi#. Thus we write that the graph repeats at each #+-n(2pi) ->+-2npi# radiand

So the period is every #+-2pi# radians.
If however you are using degrees then the repeat is every #+-360^0#

Tony B