. . . . ............x

Let θ_{1}(x) = http://upload.wikimedia.org/math/f/e...eb485cd0f6.png_{1}θ(t)dt, for x > 1

How would i go about calculating θ_{1}(6.5) using the above deﬁnition?

Am i right in thinking this is the chebyshev function?

Thanks!