find the remaining 5 trigometric functions of x
cos x = 1/5, x in quadrant 1
Construct a triangle,
you know cosx = adjacent / hypotenuse, so let the opposite be y
y^2 + 1^2 = 5^2
y = +√24 in the first quadrant.
You now have the opposite, the adjacent and the hypotenuse.
Use the definitions of the trig ratios you learned to answer your question.