Date | May 2008 | Marks available | 6 | Reference code | 08M.1.hl.TZ2.6 |
Level | HL only | Paper | 1 | Time zone | TZ2 |
Command term | Show that | Question number | 6 | Adapted from | N/A |
Question
Show that ∫π60xsin2xdx=√38−π24.
Markscheme
Using integration by parts (M1)
u=x, dudx=1, dvdx=sin2x and v=−12cos2x (A1)
[x(−12cos2x)]π60−∫π60(−12cos2x)dx A1
=[x(−12cos2x)]π60+[14sin2x]π60 A1
Note: Award the A1A1 above if the limits are not included.
[x(−12cos2x)]π60=−π24 A1
[14sin2x]π60=√38 A1
∫π60xsin2xdx=√38−π24 AG N0
Note: Allow FT on the last two A1 marks if the expressions are the negative of the correct ones.
[6 marks]
Examiners report
This question was reasonably well done, with few candidates making the inappropriate choice of u and dvdx. The main source of a loss of marks was in finding v by integration. A few candidates used the double angle formula for sine, with poor results.