Tan (-pi/2)=what?

1 Answer
Mar 4, 2018

See explanation

Explanation:

By the definition of tangent

tan(x)=sin(x)/cos(x)

So for tan(-pi/2)

tan(-pi/2)=sin(-pi/2)/cos(-pi/2)=-1/0

Which is undefined (division by 0)

However the limit must be

lim_(x->(-pi/2)^+)=tan(x)=sin(x)/cos(x)=-oo

lim_(x->(-pi/2)^-)=tan(x)=sin(x)/cos(x)=oo

Which we also can see if we graph tangent

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