ak lam z nek. 4/(x2-4) phan tich thanh 4/[(x-2)(x+2)] sau o tach thanh tong bang cach bam may tinh. suy ra: 1/(x-2) - 1/(x+2) roi toi do tu xu.hêhê. kq: -ln3
nhoc trang ak, may bai van anh lam ah doc hay gan chet ma khi phat bai cu 5,6 diem khong?(hehe) anh so minh khong du suc de thi dai hoc. khoi a1 ma em. van nua do.
bai he minh lam z dungkhong?
pt (1) bien doi x=y-a
thay vao pt (2) duoc
2y2-2y(a+1)+a2+2a-2<=0. de he co 1 nghiem thi pt nay phai co 1nghiem. hay denta = O. roi tim a.???
De linh hoat hon trong viec bien doi cac ham tich phan phuc tap. ming da tim duoc mot bai hay. cac ban cung tham khao nhe!
...tich phan di tu 0 den 1 cua x3dx/(1+x2)mu3
bai dau dat a,b la 2 can. bien doi ve phuong trinh bac 2 cua a theo b. giai ra tim duoc nghiem a=b va a=-2b-1 roi thay can vao tinh tung cai. phai khong?hj