Posted by spencer on .
sine curve in the form of y = a sin(pi/2x) that passes through the point (2.5,9.546)

precalc 
Steve,
pi/2 * 5/2 = 5/4 pi
so, we want a sin(5/4 pi) = 9.546
Since sin 5/4 pi = 1/√2, we want
a (1/√2) = 9.546
a = 13.5
So, y = 13.5 sin(pi/2 x)