Question 615761
Find all the solution of the equation in the interval (0,2pi) 
sec^2x-1=0
tan^2x=1
tan x=±√1=±1
x=π/4, 3π/4, 5π/4, and 7π/4
.. 
sinx-2=cosx-2
sinx=cosx
sinx/cosx=1
tanx=1
x=π/4 and 5π/4 in quadrants I and III where tan>0