Calc BC - can we use methods not covered in the BC curriculum on the AP?

Test Preparation AP Test Preparation
1

I was recently glancing over some of the past AP Calculus BC FRQs (namely 2007 Form B question 5) and I was wondering if we could use outside knowledge to solve problems. Question 5 can easily be solved as a first order linear DE, but would I be penalized if I used methods not covered in the BC curriculum to arrive at my answer? Thanks.