integration problem..... (1 Viewer)

[martin310015]

1. im having some trouble doin this questions.....

for the integrate x^2/(x-2)(x^2+2x+2) from 0 to -1...


i firstly used partial fractions this [x^2/(x-2)(x^2+2x+2)] becomes in the form [2/5(x-2)]+[3x+2/5(x^2+2x+2)].....got stuck...

2.int [1/(sin@+cos@)]................

thanx for any help

 

[George W. Bush]

2/5(x^2+2x+2) i assume thats the bit that's giving you trouble
remember that is equal to 2/5 ([x+1]^2 + 1)

for q2 you can use t=tanx/2 subsitution

 

[Giant Lobster]

hmmm those questions seem strange
i can't find any better way:

1) use partial fractions
2) use auxillary angle method to convert the bottom into sin

 

[nike33]

u = (x + 1)^2 followed by tanx = u works OK...ie abut a page working

 

[martin310015]

Originally posted by nike33
u = (x + 1)^2 followed by tanx = u works OK...ie abut a page working

nike33 r u talking about question 2

 

[martin310015]

for the second question by letting t=tan@/2
.....i came to int[2/(-t^2+2t+1)].........ok what should i do know....

 

[CM_Tutor]

-t² + 2t + 1 = 2 - (t - 1)² ang let u = t - 1