phong equation of illumination specular component I'm stuck on this question asking me to calculate the intensity of a pixel using Ray Tracing. It gives values such as $I_i$ but doesn't give any coordinates. 

I know for the diffuse component, $I_ik_d(n,l)$ can be written as $I_ik_d(\cos\theta)$ but for the specular component $I_ik_s(h\cdot n)$ is there any other way to write it so that it doesn't require any vectors such as $h$ and $n$?

This is the question:
Assuming that the classic Phong model is desired here, the dot product that goes into the specular calculation should be R·L, rather than N·H (which was introduced by Blinn). That is, Phong calculates specular using the angle between the reflected eye vector and the light vector.

In the diagram you posted, these vectors are shown and the angle is given as 15&deg;. So, R·L = cos(15&deg;) = 0.96 according to the table below the diagram.