Can someone help me solve this calc problem? It's attached.
Sample problem:
you have the solution with the explanation, so what else do you need?
I have a sample problem. I've tried applying the steps to the actual problem but it's confusing.
So instead of substituting 6 and 1 into the v's, you'll substitute 5 and 2.
The substitution takes place at the part where the expression is in square brackets. [ ]
You'll plug in 5 first and evaluate. Keep that answer on the side somewhere. Then you'll go back to the square brackets again, plug in 2 and evaluate. Whatever you get as the answer, you'll subtract that from the answer you got when you plugged in 5.
Can you wait while I do it, and tell me if it's correct?
Yes.
I got 77.5 when I plugged in 5.
I got -7.5
There's an extra negative sign next to the red negative sign. Ignore the extra one.
\[{-3(5)^{2}\over 2}+6(5)\]
Okay, so if I plug in 1, I'll get -3/2+8 = 6.5
No. 4.5.
Look at the equation I wrote above.
What do you get when you evaluate that expression?
Oh, I forgot to square it.
Then I get: (-7.5+4.5) - (-3/2 +8) = -9.5 or -19/2.
It's cool.
It's not correct though.
You're doing more than what it's asking for. The only values you're evaluating are 5 and 2. Not 6 and 1.
6 and 1 are solely used in the example.
You never answered my question. What do you get when you evaluate the expression I wrote above?
-7.5
Awesome. Now imagine the 5 is gone and a 2 is in its place in the expression above. What do you get now?
Replace BOTH 5s with 2s. Not just the one on the left.
6
Perfect. Now the last step is subtracting that 6 from -7.5: -7.5 - 6 =
-13.5
Awesome : )
But if you look at the sample problem, they subtracted another part too.
They subtracted the value of the expression when a 1 was plugged in. We subtracted the value of the expression when a 2 was plugged in.
I got -8 and it's still wrong.
-8 on which problem?
Ugh. It's + 8 not +6
\[{-3v ^{2} \over 2}+8v\]
Answer: -7.5 or -15/2
Okay
Sorry. I thought the expressions were the same in the example and actual problems.
It's okay. Can you help with another problem?
If you're not busy?
Sure.
Sample:
4/3
Start off exactly as the example starts by dividing u and -4 by the square root of u. This gives you: \[\int\limits_{1}^{9}u ^{1/2}-4u ^{-1/2}\]
Then integrate each term.
\[[{2 \over 3}u ^{3/2}-8u ^{1/2}]\]
Plug in 9 first, and evaluate. Plug in 1 afterwards, then evaluate. Subtract the second answer from the first one.
Take care and don't forget to mark a Best Response. Thank you
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