# 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)
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
Original post by alquinton

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)