Hello everyone: Problem Set 2 (Unit 2. Applications of Differentiation, 2A-6)
I can do it using the basic approximation formulas, i.e. f(x)~=f(a)+f'(a)(x-a)+f"(a)(x-a)^2, but the answer I think is done algebraically: I really can't figure this out and I probably missed the bit of video where they mention this method? Thanks!

Question

Hello everyone: Problem Set 2 (Unit 2. Applications of Differentiation, 2A-6)
I can do it using the basic approximation formulas, i.e. f(x)~=f(a)+f'(a)(x-a)+f"(a)(x-a)^2, but the answer I think is done algebraically: I really can't figure this out and I probably missed the bit of video where they mention this method? Thanks!

anonymous · Answer

I assume this is what you referred to, "Find a quadratic approximation to tan θ, for θ ≈ 0".
Yeah, it's solved using the basic approximation formula.

anonymous · Answer

I got it now: I used (tanx)' and (tanx)" directly where as the answer uses the approximation for sinx and cosx instead. Thanks!