# Thread: Integrals using step functions

1. ## Integrals using step functions

I have the integral from 1 to 5 of [h(t-2) + h(t)]lnt dt

I broke this integral into integral from 1 to 5 of [h(t-2)ln t] + integral from 1 to 5 of [h(t) lnt]

but now I don't know how to actually use the step function to find the answer..

I have the integral from 1 to 5 of [h(t-2) + h(t)]lnt dt

I broke this integral into integral from 1 to 5 of [h(t-2)ln t] + integral from 1 to 5 of [h(t) lnt]

but now I don't know how to actually use the step function to find the answer..
Do you know the definition of the step function? If so, apply it to your problem ....

3. h(t - a) = 1 if t>= a and 0 if t<a ? but uumm how do i know what t is..? :S

4. Wait is it because its bewteen 1 to 5?? so if its in between there we can say it is equal to 1 and if it is not then it is equal to 0?

5. Actually I don't understand it..

I have h(t-2) = 1 when t>=2 and 0 when t < 2

With the integral from 1 to 5 of h(t-2)lnt do i do integral from 1 to 2 of lnt x 0 is equal to zero then plus integral from 2 to 5 of lnt x 1?