Possible intermediate steps:
integral (sin(sqrt(t)))/sqrt(t) dt
For the integrand (sin(sqrt(t)))/sqrt(t),substitute u = sqrt(t) and du = 1/(2 sqrt(t)) dt:
= 2 integral sin(u) du
The integral of sin(u) is -cos(u):
= -2 cos(u)+constant
Substitute back for u = sqrt(t):
= -2 cos(sqrt(t))+constant
简单来说,变量替换
u=根号t