Integral Question! Thanks in advance!

Question

anonymous · Answer

attachment

bahrom7893 · Answer

integrate that from 0 to 4

anonymous · Answer

but the equation at t=0 doesn't equal 70 so I'm confused or does that not matter? @bahrom7893

bahrom7893 · Answer

No that's the rate of how the increase. You need the actual increase.

anonymous · Answer

I got 916.8 but that was incorrect when I put in the answer

anonymous · Answer

@bahrom7893

anonymous · Answer

@FutureMathProfessor is there anyone you can help? I've gotten the same answer multiple times and I can't figure out what I'm doing wrong

anonymous · Answer

solve as a differential equation rather than an integral.

$$\frac{ dP }{ dt } = 210 + 8t + 0.6t^2$$

$$\int\limits_{}^{} dP = \int\limits_{}^{} 210 + 8t + 0.6t^2 dt$$

$$P(t) = 210t + 4t^2 + 0.2t^3 + C$$

given in question that P(0) = 70 --> plugging this in above gives C = 70

so your solution is now:

$$P(t) = 210t + 4t^2 + 0.2t^3 + 70$$

plug in 4 in P(t)

anonymous · Answer

@Euler271 I've also tried that and it was incorrect as well :(

anonymous · Answer

what is the answer?

anonymous · Answer

I don't have it I have 7 attempts remaining

anonymous · Answer

my method gives 986.8


another "method" i jotted down gives 321.6. you should try 986.8 first though

anonymous · Answer

I have tries 986.8 986 and 987 I have also tried 916.8 916 and 917 none are correct this is a pain thank you for attempting to help me

anonymous · Answer

321.6 was also incorrect

anonymous · Answer

no problem

webwork isn't necessarily right btw. i went nuts one night lol

anonymous · Answer

I know it isn't! It is just frustrating when I have done my homework and understand it but don't get a 100 on it :( haha thanks for your help though