Apakah int xln (x) ^ 2?

Apakah int xln (x) ^ 2?
Anonim

Jawapan:

Sekiranya anda maksudkan #ln (x) ^ 2 = (lnx) ^ 2 #

Anda perlu mengintegrasikan dengan bahagian dua kali. Jawapannya ialah:

# x ^ 2/2 (ln (x) ^ 2-lnx + 1/2) + c #

Sekiranya anda maksudkan #ln (x) ^ 2 = ln (x ^ 2) #

Anda perlu mengintegrasikan dengan bahagian sekali. Jawapannya ialah:

# x ^ 2 (lnx-1/2) + c #

Penjelasan:

Sekiranya anda maksudkan #ln (x) ^ 2 = (lnx) ^ 2 #

#intxln (x) ^ 2dx = #

# = int (x ^ 2/2) 'ln (x) ^ 2dx = #

# = x ^ 2 / 2ln (x) ^ 2-intx ^ 2/2 (ln (x) ^ 2) 'dx = #

Batalkan (2) lnx * 1 / cancel (x) dx = #

# = x ^ 2 / 2ln (x) ^ 2-intxlnxdx = #

# = x ^ 2 / 2ln (x) ^ 2-int (x ^ 2/2) 'lnxdx = #

# = x ^ 2 / 2ln (x) ^ 2- (x ^ 2 / 2lnx-intx ^ 2/2 (lnx) 'dx) = #

# x ^ 2 / 2ln (x) ^ 2- (x ^ 2 / 2lnx-intx ^ cancel (2) / 2 * 1 / cancel (x) dx)

# = x ^ 2 / 2ln (x) ^ 2- (x ^ 2 / 2lnx-1 / 2intxdx) = #

# = x ^ 2 / 2ln (x) ^ 2- (x ^ 2 / 2lnx-1 / 2x ^ 2/2) + c =

# = x ^ 2 / 2ln (x) ^ 2- (x ^ 2 / 2lnx-x ^ 2/4) + c = #

# = x ^ 2 / 2ln (x) ^ 2-x ^ 2 / 2lnx + x ^ 2/4 + c = #

# = x ^ 2/2 (ln (x) ^ 2-lnx + 1/2) + c #

Sekiranya anda maksudkan #ln (x) ^ 2 = ln (x ^ 2) #

#intxln (x) ^ 2dx = intx * 2lnxdx #

# 2intxlnxdx = #

# = 2int (x ^ 2/2) 'lnxdx = #

# = 2 (x ^ 2 / 2lnx-intx ^ 2/2 * (lnx) 'dx) = #

# = 2 (x ^ 2 / 2lnx-intx ^ cancel (2) / 2 * 1 / cancel (x) dx) = #

# = 2 (x ^ 2 / 2lnx-1 / 2intxdx) = #

# = 2 (x ^ 2 / 2lnx-1 / 2x ^ 2/2) + c = #

# = membatalkan (2) * x ^ 2 / (batalkan (2)) (lnx-1/2) + c = #

# = x ^ 2 (lnx-1/2) + c #