Can someone help me how to answer this?

[SomeDedPerson]

Question
Write an equation that describes the relation between tan x and tan(90-x).

So i know that tan x = b/a, tan(90-x) = a/b, but what are the next steps to create that equation?

 

[LCKurtz]

[imath]\tan x = \frac b a = \frac 1 {\frac a b} = \frac 1 {\tan(\frac \pi 2 -x)}, 0 < x < \frac \pi 2[/imath]

 

[Steven G]

How about tan(x)*tan(90-x) = 1? Is this always true?