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A level maths help

1. prove that sec^4theta - tan^4theta = sec^2theta+tan
^2theta


2. hence solve the interval -180deg < theta<180deg, sec^4theta = tan^4theta+3tantheta

I have the answer for part 1 i just need part 2
(edited 1 month ago)
Reply 1
Original post by cheery-condition
1. prove that sec^4theta - tan^4theta = sec^2theta+tan
^2theta


2. hence solve the interval -180deg < theta<180deg, sec^4theta = tan^4theta+3tantheta

I have the answer for part 1 i just need part 2
Looks like youd just use the first part and note you can use the pythagorean identity for sec^2 to end up with an equation in tan which can be solved.
Original post by cheery-condition
1. prove that sec^4theta - tan^4theta = sec^2theta+tan
^2theta


2. hence solve the interval -180deg < theta<180deg, sec^4theta = tan^4theta+3tantheta

I have the answer for part 1 i just need part 2
Post what you've tried please :smile:
Reply 3
Original post by alquinton
Post what you've tried please :smile:

take the equation in part 2....
.

Please remove the details of your post - it's against forum rules to post solutions!
(edited 1 month ago)

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