If f(x) = sin[π^2]x+sin[-π^2]x, where [x]denotes greatest Integer less than or equal to x, then
Answer : f(x) = sin(9x) - sin(10x)
As we know that π = 3.14.
Then, (π)(π) ~ 9.(something) i.e. 9 < (π)^2 < 10
Now…
greatest integer of (π)^2 = greatest integer of 9.(something) = 9
greatest integer of -(π)^2 = greatest integer of -9.(something) = -10
Substituting these values in f(x), we get…
f(x) = sin(9x) + sin(-10x),
f(x) = sin(9x) - sin(10x) [As: sin(-x) = -sin(x)]
You did not give specific value of x for which you want to know f(x) value i am going to give two example
Now,
f(π/2) = sin(9π/2) - sin (10π/2) = sin(9π/2) + sin(5π)
= sin(4π + π/2) - sin(4π + π)
= sin(π/2) - sin(π)
= 1 - 0 = 1
Similarly you can find any value of f(x) by simply substitute and find other values of f(x) when x is given.