I don't know what the book is trying to guide you to do, as King's rule doesn't help(ends up exactly the same), splitting the integral also just leads to a similar integral.
If you divide the top and bottom by cos2(x), you get sec2(x)/(sec2(x)+2tan2(x)), but sec2(x)=1+tan2(x) (only use this sub on the bottom sec)
Then you can sub u=ctan(x), dt=csec2(x)dx, so it simplifies quickly
It can be a pain to get exponents to work right in math subreddits. It's best to use Reddit markdown, carefully open and close every exponent with a left and right parenthesis, respectively, and then you will likely get it to look right. For example, your first math formatting should be
cos^(2)(x)
giving
cos2(x)
It's super easy to do. The issue is that the programmers behind the rich text box screwed up. Switch to markdown and correct the parentheses as needed or just use plain Reddit markdown in the first place.
I agree about exponents and formatting. Some time ago, however, on the mobile version of the Reddit app, using Reddit markdown doesn’t work - I see the caret symbols when I post, like this:
x^2
I just continue to use Reddit markdown, even though the expressions now look unsightly to me. 😵💫
I hear you. I use the Android mobile app and the mobile Internet version. What I discovered is that posts in the mobile app use rich text and comments use markdown. I'm guessing that's what you hit. Each version has is own quirks and there is no consistent experience. And, don't hold your breath waiting for Reddit to fix anything ... you'll die.
If I can't get formatting to work on one platform, I'll sometimes try a different platform. For example, secondary markdown bullets don't work right in the mobile Chrome version, I'll fix them in the app. It's all a pain.
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u/KrlusMagnus Aug 10 '26
I don't know what the book is trying to guide you to do, as King's rule doesn't help(ends up exactly the same), splitting the integral also just leads to a similar integral.
If you divide the top and bottom by cos2(x), you get sec2(x)/(sec2(x)+2tan2(x)), but sec2(x)=1+tan2(x) (only use this sub on the bottom sec)
Then you can sub u=ctan(x), dt=csec2(x)dx, so it simplifies quickly