Question

How to prove this identity: 1-sin2x/cosx = cosx?

Answer 1

do I expand sin2x? eep.

Answer 2

is that sin (2x) or sin^2 x?

Answer 3

sin^2x

Answer 4

lemme rephrase that..
\[\frac{1 - \sin^2x}{\cos^2x}\]

Answer 5

yup

Answer 6

i mean cos x

Answer 7

okay

Answer 8

change \(1 - \sin^2x\) into one of the good old trig identities

Answer 9

is that sin2x or sin^2x

Answer 10

cos^2x?

Answer 11

got it!

\[\frac{\cos^2 x}{\cos x}\] simplify that

Answer 12

lol mimi :P

Answer 13

\(sin^2x+cos^2x=1\)
=> \(cos^2x=1-sin^2x\)

Answer 14

ohhh, i cancel: cosxcosx/cosx?

Answer 15

\[\frac{\cancel{(\cos x)}(\cos x)}{\cancel{\cos x}}\]