2024 AP Calculus AB/BC Free Response #1

Walkthrough of the 2024 AP Calculus AB/BC FRQ #1

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[fireball]

I dont really agree with D. The rate itself technically may be increasing (becoming less negative), but the temperature is changing overall (abs value) at a decreasing rate since the first and second derivatives are different signs.

[icii]

I said the coffee’s temperature is decreasing at a decreasing rate because the second derivative was positive. that is technically true because the second derivative is positive and the first derivative is negative so it will be decreasing less and less. Will I get credit 😶

[ItsODRJR]

Just remembered I forgot to put units I’m cooked

[so.phiaaa]

i'm cooked, fried, baked. got 1/9 correct

[eSwagYT]

doesn’t part d ask for if it’s changing at an increasing or decreasing rate? so bc the temperature is decreasing but the second derivative is positive the rate at which the temperature is changing is decreasing? negstivd first derivative positive second derivative. decreasing rate???

[thereliabledavid]

For b it never says to actually calculate the average value, just interpret what it would mean, so would I lost points for not calculating it but just explaining what it would mean?

[minmin-tjbh]

Should Part D be decreasing at a decreasing rate? Since it is concave up because the second derivative is positive, and it is decreasing because the first derivative is negative, the temperature should be decreasing but at a decreasing rate.

[howaydafayyad]

For 1 d. you need to demonstrate that c'(t) is less than zero, c(t) is decreasing and then do the c"(t) as you did.

[YourHealthGuide-rd]

Did we need to put units after 985? Cuz it didn’t ask for them and plus it’s a riemann sum.. I put units for all the other parts tho so how many points will I lose

[Dollaboi]

Would “total avg change in temperature is 985/12 from 0 to 12 mins” work for the interpretation

[niftyfountain]

for some reason, i had a different version so i had other frqs than everyone else is there going to be another video covering the other version?

[arhanahmed]

So for part a I only put -4 c/min, will it be wrong since I didn’t put degrees?

[Dollaboi]

Also how may points would I get off if for part b I put my approximation as 80.083 but had all the work for the right Reimen sum and 985 written on my paper

[ryderopskar]

would increasing at a decreasing rate count?

[lukasbl]

for D can u also just take the integral over the time and see that the rate is increasing meaning the temperature is increasing over that time

[benrobs]

9/9 makes up for leaving half of number 5 blank

[ealize]

Did we actually need to solve for the average value? I just said it was the average value of the temperature of the coffee in degrees Celsius from 0 to 12 minutes… oops