Posted by Jesssica on .
I'm trying to do this identities homework and i can't figure this one out.
sec^4x + (tan^2x)(sec^2x)= sec^4x

PreCal 
Anonymous,
There must be a typo somewhere. If you subtract sec^4x from both sides, you have
tan^2x * sec^2x = 0
which is not always true.