Verify the Identity!
( tan^4 x - sec^4 k) = (1 - 2 sec^2 k)
Please help me! I'm sure this is a no brainer, but I have no clue how to solve this, I've tried many times and OS is my last resort, please explain how to solve this, anyone! :( please and thank you :O

Question

Verify the Identity!
( tan^4 x - sec^4 k) = (1 - 2 sec^2 k)
Please help me! I'm sure this is a no brainer, but I have no clue how to solve this, I've tried many times and OS is my last resort, please explain how to solve this, anyone! :( please and thank you :O

anonymous · Answer

try this:$$\Large \tan^2\alpha-1=\sec^2(\alpha) $$

anonymous · Answer

$$\Large \tan^2x=\sec^2x-1 $$
Squaring both sides and that will do.

anonymous · Answer

Sorry, should be a plus of course. Here again:$$\Large \tan^2x=\sec^2x+1 $$

anonymous · Answer

$$
a^2-b^2=(a-b)(a+b)
$$

anonymous · Answer

$$
\tan^2x+1 = \sec^2x
$$

anonymous · Answer

yes you're right @wio, I messed this one up.

anonymous · Answer

@Ikushinkan Still need help?

anonymous · Answer

is this really an identity with two variables "x" and "k" ???

anonymous · Answer

@spacelimbus

You get the identity wrong; it's: tan^2(x) + 1 = sec^2(x)