Quick question on why I got something wrong

**NeedDirection** · November 15th 2011, 11:30 PM

I was given $\int^4_0 f(x)\,dx = 4$

I was asked to evaluate the following:
$\int^4_0 (3*f(x)+1)\,dx$

What I simply did was took $3*4+1=13$ and I was marked down a point. How is this incorrect? I'm sure it's something stupid I am not seeing but I can't seem figure it out!
Thanks

**Opalg** · November 16th 2011, 12:02 AM

Originally Posted by NeedDirection

I was given $\int^4_0 f(x)\,dx = 4$

I was asked to evaluate the following:
$\int^4_0 (3*f(x)+1)\,dx$

What I simply did was took $3*4+1=13$ and I was marked down a point. How is this incorrect? I'm sure it's something stupid I am not seeing but I can't seem figure it out!
Thanks

What is $\int_0^41\,dx$ ?

**FernandoRevilla** · November 16th 2011, 12:03 AM

Originally Posted by NeedDirection

What I simply did was took $3*4+1=13$ and I was marked down a point. How is this incorrect? I'm sure it's something stupid I am not seeing but I can't seem figure it out!

The solution is not $13$ :

$\int_0^4(3f(x)+1)dx=\int_0^43f(x)dx+\int_0^41dx=$

$3\int_0^4 f(x)+[x]_0^4=3\cdot 4+(4-0)=16$

Edited: Sorry, I didn't see Opalg's post.

**NeedDirection** · November 16th 2011, 12:27 AM

Just as I expected, something simple I couldn't see!
Thanks guy's!

Thread: Quick question on why I got something wrong

LinkBack

Thread Tools

Display

Quick question on why I got something wrong

Re: Quick question on why I got something wrong

Re: Quick question on why I got something wrong

Re: Quick question on why I got something wrong

Similar Math Help Forum Discussions

another probability question, i am doing it wrong as i get 1.5

Lost on Question 18...What am I doing wrong???

Determinants Question What did I do Wrong?

Exam tomorrow.Quick simulataneous equation I'm getting wrong!

Quick's quick question

Search Tags