Question #bd476

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Answer 1 · 2017-08-17T23:08:29

#tan(x)=+-1#

#sec(x)^2= tan(x)^2+1#

derived from #sin(x)^2+cos(x)^2=1# divide all by cos(x)^2

#2tan(x)^2-(tan(x)^2+1)#

#2tan(x)^2-tan(x)^2-1=0#

#tan(x)^2=1#

#tan(x)=+-1#

#tan(x)#can be equal to

#{ − 45 ∘ , 45 ∘ , 135 ∘ , 225 ∘ } .#