c[−π/2, π/2], f(x) = sin(x), g(x) = cos(x)
a) Find the inner product of f and g using the given inner product formula
b) Calculate the integral of the product of f(x) and g(x) over the interval [-π/2, π/2]
c) Use the orthogonality condition to determine if the inner product of f and g is zero
d) Check if f and g are perpendicular by testing if their inner product equals zero