The graph of a sinusoidal function intersects its midline at (0,-3)(0,−3)left parenthesis, 0, comma, minus, 3, right parenthesis and then has a maximum point at (2,-1.5)(2,−1.5)left parenthesis, 2, comma, minus, 1, point, 5, right parenthesis. Write the formula of the function, where xxx is entered in radians. f(x)=f(x)=f, left parenthesis, x, right parenthesis, equals