5 ways to avoid distractors on the ap calculus multiple choice section

what are distractors and how do you avoid them on a standardized test like the ap calculus exam? a distractor is an incorrect answer choice. here are five ways to detect and avoid them in the multiple choice section.

what are distractors?

in a multiple choice question, one of the answer choices is the correct one. distractors are all of the others — the incorrect choices.

the main reason that the incorrect choices are called distractors is that they may seem to be correct, distracting you away from the actual correct choice.

test makers spend a lot of time coming up with good distractors. it’s not just a matter of including a few random incorrect choices alongside the correct one. there are reasons for each distractor in the list.

some incorrect choices represent the result of common student errors. others are very close numerically to the correct choice so that you really have to compute your answer with precision.

now let’s take a look at five ways to avoid those distracting incorrect choices on the ap calculus multiple choice section.

tip #1: avoid the common mistakes

this is easier said than done of course. however, the incorrect choices under an ap calculus multiple choice question typically show the common mistakes that students make.

the best way to avoid common mistakes is to practice, practice, practice! take a number of practice exams before the real deal.

how many? well check out this post for advice: how many ap calculus practice problems should i do?

tip #2: be suspicious of simple answers

less is not more in an ap calculus exam.

while there are cases in which the simple answer ends up being the correct one, often times the simple answers demonstrate some misuse of calculus formulas.

here’s one of my favorite examples.

example

what is the derivative of x^x?

a. x(x^x-1)

b. x^xln x

c. x^x(1 + ln x)

d. x^x-1 ln x

simple right? the power rule would give you x(x^x-1), right?

well not so fast! what about the exponential rule? that would give you x^xln x.

so which one is correct?

it turns out that neither answer is correct. instead, using logarithmic differentiation, you may find that the correct derivative is actually x^x(1 + ln x), letter choice c.

the simpler choices, a and b, were merely distractors.

tip #3: the closest number is not always the best

sometimes when you work out a problem, your answer does not match the given choices. this can be very frustrating, but don’t just look for the closest number in the list.

instead, go back through your work and see if there was an error somewhere. something as simple as a misplaced negative or forgetting to distribute a constant could lead you down the wrong path.

tip #4: look for differences in the answers

a right answer may be transformed into a wrong answer just by changing one small feature. read each answer choice and carefully note what makes each one different from the rest. that way you can pick out the right one based on your work.

for instance, if both x – 1 and x² – 1 show up as answer choices, you have to be aware that the second one has a square on the x while the first does not.

tip #5: take your time

i know, i know… the ap calculus ab or bc exam is a timed test. speed is of the essence!

however, it’s no good to rush through all of the questions if it means you’re having to guess at the answers or making common errors (see tip #1).

summary

so let’s review. the five ways to avoid distractors are:

1. avoid the common mistakes.
2. be suspicious of simple answers.
3. the closest number is not always the best.
4. look for differences in the answers.
5. take your time.

even if you can’t avoid them all, if you can eliminate an incorrect choice or two then your chances of guessing the correct answer goes up. check out this post for more tips: ap calculus review: process of elimination technique.