Question 1141807
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The second part of what you say you know is useful, because it writes the sin^2(t) in terms of cos(t).<br>
The first part of what you say you know doesn't help, because it writes sec^2(t) in terms of tan^2(t).<br>
You want to do the same thing with the sec^2(t) that you did with the sin^2(t) -- write it in terms of cos(t).<br>
So... what is the relationship between sec(t) and cos(t)?