Hi. Looking for help on another trig proof. Here's the problem.

Prove that:

sec^6x (secx.tanx) - sec^4x (secx.tanx) =sec^5x.tan^3x

This one's got me baffled. Thanks in Advance,

Mike Clemmons

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- Jan 28th 2010, 03:23 PMMike ClemmonsTrig proof/verification help
Hi. Looking for help on another trig proof. Here's the problem.

Prove that:

sec^6x (secx.tanx) - sec^4x (secx.tanx) =sec^5x.tan^3x

This one's got me baffled. Thanks in Advance,

Mike Clemmons - Jan 28th 2010, 03:36 PMpickslides
What have you tried?

Can I suggest taking out $\displaystyle \sec x \tan x$ as a common factor first on the LHS

so

$\displaystyle (\sec x \tan x)(\sec^6 x- \sec^4 x)$

$\displaystyle (\sec x \tan x)(\sec^4 x(\sec^2 x- 1))$

$\displaystyle (\sec x \tan x)(\sec^4 x(\tan^2 x))$

The rest should be easy...