Question

simplify the expression:
(secx+cosx)(secx-cosx)
I know it goes to sec^2x-cos^2x but i'm supposed to get tan^2x+sin^2x can anyone help me?

Answer 1

idk what to do >.<'

Answer 2

Sec^2[x]=1+Tan^2[x] and Cos^2[x]=1-Sin^2[x]. Plug those into Sec^2[x]-cos^2[x] to get (1+tan^2[x])-(1-sin^2[x]). This simplifies to Tan^2[x]+sin^2[x]

Answer 3

Got it?

Answer 4

yup ^^ thx