求 根号(1+2^t) 的积分∫根号(1+2^t)
1个回答

是:∫(1+2^t)^0.5dt

令1+2^t=x

t=log2(x-1)

dt=1/[(x-1)ln2]dx

原式=1/ln2*∫x^0.5/(x-1)dx

=2/3*1/ln2*∫1/(x-1)d(x^3/2)令:x^3/2=u.

=2/(3ln2)*∫1/(u^1/3+1)(u^1/3-1)du

=1/3ln2*[∫1/(u^1/3-1)du-∫(u^1/3+1)du]令:u^1/3=q

=1/ln2*[∫q^2/(q-1)dq-∫q^2(q+1)dq]

=1/ln2*∫q^2/(q^2-1)dq

=1/ln2*[∫1dq+∫1/(q^2-1)dq]

下面我不做了,你自己可以解出来.