The points (2/3,5/2)(23,52) and (4,15)(4,15) fall on the same line and therefore the terminal side of the same angle, thetaθ, and the second point is easier to work with. (I basically multiplied through by 6 to scale the point up.)
Calculate r=sqrt(4^2+15^2)=sqrt(16+225)=sqrt(241)r=√42+152=√16+225=√241.
Knowing xx, yy, and rr we can find:
cos(theta)=x/rcos(θ)=xr, sin(theta)=y/rsin(θ)=yr, and tan(theta)=y/xtan(θ)=yx.
For this problem we have:
cos(theta)=4/sqrt(241)cos(θ)=4√241, sin(theta)=15/sqrt(241)sin(θ)=15√241, and tan(theta)=15/4tan(θ)=154.
The remaining functions are found by taking reciprocals:
sec(theta)=sqrt(241)/4sec(θ)=√2414, csc(theta)=sqrt(241)/15csc(θ)=√24115, and cot(theta)=4/15cot(θ)=415.