FP3 Integration Help/C4 Integration

PaigeS1997

Using integration by parts, ntegral(arcsin(x/2)dx
Limits root3 and 0

I keep getting the wrong answer and I'm not sure why

I used u=arcsin(x/2)
u'=1/2squareroot(1-1/4x^2)

v'=1
v=1

Can anyone help please?

Thank you in advance to anyone that helps.

(edited 8 years ago)

Reply 1

TeeEm

19

Original post by PaigeS1997

Using integration by parts, show that integral(arcsin(x/2)dx=1/8
Limits root3 and 0

I keep getting the wrong answer and I'm not sure why

I used u=arcsin(x/2)
u'=1/2squareroot(1-1/4x^2)

v'=1
v=1

Can anyone help please?

Please post a photo of your workings

Reply 2

PaigeS1997

OP

1

Original post by TeeEm

Please post a photo of your workings

When I entered the limits the answer was wrong

Original post by PaigeS1997

When I entered the limits the answer was wrong

it is your very last line, the very last term you integrated

Reply 4

PaigeS1997

OP

1

Original post by TeeEm

it is your very last line, the very last term you integrated

Thank you, I see now that I have an extra x on it

(edited 8 years ago)

Reply 5

TeeEm

19

Original post by PaigeS1997

Thank you very much

no worries

Reply 6

PaigeS1997

OP

1

Original post by TeeEm

no worries

Sorry to be a pain but what do I actually do with that x in order to integrate please?

Reply 7

TeeEm

19

Original post by PaigeS1997

Sorry to be a pain but what do I actually do with that x in order to integrate please?

For some students this is recognisable

otherwise use the substitution

u = 4 - x²

^PS
^{the a a far better way of doing this integral.}
^{Post your correct solution first so I cannot be accused of posting full solutions, and I will then post an alternative}

Reply 8

PaigeS1997

OP

1

Original post by TeeEm

For some students this is recognisable

otherwise use the substitution

u = 4 - x²

^PS
^{the a a far better way of doing this integral.}
^{Post your correct solution first so I cannot be accused of posting full solutions, and I will then post an alternative}

Got it thank you

Reply 9

PaigeS1997

OP

1

Original post by TeeEm

For some students this is recognisable

otherwise use the substitution

u = 4 - x²

^PS
^{the a a far better way of doing this integral.}
^{Post your correct solution first so I cannot be accused of posting full solutions, and I will then post an alternative}